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1Higher Level, Educate.ie Sample Paper Solutions
Sample Paper 1 Educate.ie Paper 1 Solutions ....................................................................... 2
Educate.ie Paper 2 Solutions ..................................................................... 16
Sample Paper 2 Educate.ie Paper 1 Solutions ..................................................................... 26
Educate.ie Paper 2 Solutions ..................................................................... 34
Sample Paper 3 Educate.ie Paper 1 Solutions ..................................................................... 44
Educate.ie Paper 2 Solutions ..................................................................... 56
Sample Paper 4 Educate.ie Paper 1 Solutions ..................................................................... 68
Educate.ie Paper 2 Solutions ..................................................................... 77
Sample Paper 5 Educate.ie Paper 1 Solutions ..................................................................... 88
Educate.ie Paper 2 Solutions ..................................................................... 99
Sample Paper 6 Educate.ie Paper 1 Solutions ................................................................... 111
Educate.ie Paper 2 Solutions ................................................................... 122
Sample Paper 7 Educate.ie Paper 1 Solutions ................................................................... 133
Educate.ie Paper 2 Solutions ................................................................... 143
ContentS
educate.ie MAtHeMAtICS SoLUtIonS
Leaving Certificate Higher Level
Educate.ie’s Leaving Certificate Higher Level Sample Paper Mathematics Solutions are also available on www.educateplus.ie.
2 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 2 (25 marks)
( )( )3 2 3 2
3 6 6 2 1
− +
= + − − =
3 23 2
3 23 2
3 23 2
5 2 61
5 2 6
+−
=+−
×++
=+
= +
( )( )
( )( )
[theme: All about irrationals, root 2 and root 3]
z i
iz
z
12 1212
1212
1
26 6
2 126
126
= +
= +
cos sin
cos sin
π π
π π
22
12
12
12 12
2 2 2
2 1 0 2
= +{ }
= +{ }=
cos sin
( )
π πi
iz
Question 1 (e)
Question 2 (a)Draw a circle with centre (0, 0) through the point (1, 1).The radius of this circle is r = − + − =( ) ( ) .1 0 1 0 22 2
Question 2 (b) (i)
Question 2 (b) (ii) Question 2 (b) (iii)
zw i i i= +
+
= +2
6 62 2
323
4 56
5cos sin cos sin cos sinπ π π π π π66
4 56
150
= = =zw zw, arg π o
Question 1 (d)When you multiply complex numbers in polar form you add their arguments.
(De Moivre’s Theorem)
2
0�2 �1
y
21
1
P
�2
�1
2
x2 is the distance of (0, 0) to P on this scale.
Or (use the difference of 2 squares)
( )( )
( ) ( )
3 2 3 2
3 23 2 1
2 2
− +
= −= − =
( )
( ) ( )
3 2
3 2 3 2 2
3 2 6 2
5 2 6
2
2 2
+
= + +
= + +
= +
[ (cos sin )] (cos sin )r i r n i nn nq q q q+ = +
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 1 (25 marks)
z r z= =, arg θ
z r i= +(cos sin )θ θz i
z z
= +
= = =
26 6
26
30
cos sin
, arg
π π
π o
Im
Re
1
2
z
4
0�1�2�3�4 1 2 3 4
�1
�2
�3
�4
3
kz
30o
izzw
30o
Question 1 (a)
kz i kz kz= +
⇒ = = =4
6 64
630cos sin , argπ π π o
w iz= = +
+
= +
+
12 2
26 6
22 6
cos sin cos sin
cos
π π π π
π π ii
i
w w
sin
cos sin
, arg
π π
π π
π
2 6
2 23
23
2 23
1
+
= +
= = = 220o
Question 1 (b)
Question 1 (c)
Multiplying by i rotates a complex number by 90o anticlockwise.
sample paper 1: paper 1
Write i as a complex number in polar form: i i i= + = +
0 1 1
2 2cos sinπ π
[When you multiply complex numbers in polar form you add their arguments.]
Higher Level, Educate.ie Sample 1, Paper 1 3
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 2 (25 marks)
( )( )3 2 3 2
3 6 6 2 1
− +
= + − − =
3 23 2
3 23 2
3 23 2
5 2 61
5 2 6
+−
=+−
×++
=+
= +
( )( )
( )( )
[theme: All about irrationals, root 2 and root 3]
z i
iz
z
12 1212
1212
1
26 6
2 126
126
= +
= +
cos sin
cos sin
π π
π π
22
12
12
12 12
2 2 2
2 1 0 2
= +{ }
= +{ }=
cos sin
( )
π πi
iz
Question 1 (e)
Question 2 (a)Draw a circle with centre (0, 0) through the point (1, 1).The radius of this circle is r = − + − =( ) ( ) .1 0 1 0 22 2
Question 2 (b) (i)
Question 2 (b) (ii) Question 2 (b) (iii)
zw i i i= +
+
= +2
6 62 2
323
4 56
5cos sin cos sin cos sinπ π π π π π66
4 56
150
= = =zw zw, arg π o
Question 1 (d)When you multiply complex numbers in polar form you add their arguments.
(De Moivre’s Theorem)
2
0�2 �1
y
21
1
P
�2
�1
2
x2 is the distance of (0, 0) to P on this scale.
Or (use the difference of 2 squares)
( )( )
( ) ( )
3 2 3 2
3 23 2 1
2 2
− +
= −= − =
( )
( ) ( )
3 2
3 2 3 2 2
3 2 6 2
5 2 6
2
2 2
+
= + +
= + +
= +
[ (cos sin )] (cos sin )r i r n i nn nq q q q+ = +
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 1 (25 marks)
z r z= =, arg θ
z r i= +(cos sin )θ θz i
z z
= +
= = =
26 6
26
30
cos sin
, arg
π π
π o
Im
Re
1
2
z
4
0�1�2�3�4 1 2 3 4
�1
�2
�3
�4
3
kz
30o
izzw
30o
Question 1 (a)
kz i kz kz= +
⇒ = = =4
6 64
630cos sin , argπ π π o
w iz= = +
+
= +
+
12 2
26 6
22 6
cos sin cos sin
cos
π π π π
π π ii
i
w w
sin
cos sin
, arg
π π
π π
π
2 6
2 23
23
2 23
1
+
= +
= = = 220o
Question 1 (b)
Question 1 (c)
Multiplying by i rotates a complex number by 90o anticlockwise.
sample paper 1: paper 1
Write i as a complex number in polar form: i i i= + = +
0 1 1
2 2cos sinπ π
[When you multiply complex numbers in polar form you add their arguments.]
Sample 1
Paper 1
4 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 3 (25 marks)
lim lim( )
lim( )n n
nn
n
nn
nn→∞ →∞ →∞+
=+
=+
=2
3 423
23
234 4
Question 3 (a) (i)
Question 3 (a) (ii) Question 3 (a) (iii)
Question 3 (b) (i)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
[You can use the technique shown for finding the limit or you can find the limit by inspection.]
Terms of a geometric sequence: a ar ar ar arn, , , ,............,2 3 1−
1. Prove true for n = 1: S a rr
a1
111
=−−
=( )
[Therefore, true for n = 1.]
2. Assume true for n = k: Assume S a ar ar a rrk
kk
= + + + =−−
−............. ( )1 11
3. Prove true for n = k + 1: Prove S a ar ar ar a rrk
k kk
+−
+
= + + + + =−−1
111
1............. ( )
Proof:
( ............. ) ( )
(
a ar ar ar a rr
ar
a r
k kk
k
k
+ + + + =−−
+
=−
−1 11
1 )) ( )
( )
+ −−
=− + −
−
=−−
+
+
ar rr
a ar ar arr
a rr
k k k k
k
11 1
11
1
1
lim ,n
nr r→∞
= <0 1 lim ,n
nr r→∞
= ∞ >1
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
lim ( ) limn
n
n
n
→∞ →∞= = ∞
13
2 13
2lim limn
n
n
n
→∞ →∞
=
= × =
2 13
2 13
2 0 2
lim ,n
nr r→∞
= <0 1lim lim ( ) lim( ) ( limn n n
n
n
n
n
nS a rr
ar
r ar
r→∞ →∞ →∞ →∞
=−−
=−
− =−
−11 1
11
1 ))
( )=−
− =−
ar
ar1
1 01
Question 3 (b) (ii)
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
log log ( )
log ( )
( ) ( )
2 2
2
2 4 4 2
2
4 4
4 4
4 2 2 2 44 4
12
x x
x x
x xx x
+ + =
+ =
+ = = = =
+ − ==
=− ± − −
=− ± +
=− ±
=− ±
= − ±
>
0
4 4 4 1 42 1
4 16 162
4 322
4 4 22
2 2 2
0
2
x
x
( ) ( )( )( )
⇒⇒ = −x 2 2 2
Question 2 (c) (i)
x b b aca
=− ± −2 4
2
x xx x
2
2
2 12 1 0
− >
− − >
x x
x
2
2
2 1 0
2 2 4 1 12 1
2 4 42
2 82
2 2 22
1 2
− − =
=− − ± − − −
=± +
=±
=±
= ±
( ) ( ) ( )( )( )
x x x< − > + ∈1 2 1 2, , �
Question 2 (c) (ii)
[Solve the equality using the quadratic formula.]
SoLutionS:
Carry out the region test, or whatever test you use, to locate the regions that satisfy the inequality:
1 2+1 2−
ª 2 41.≈ −0 41.
−1 0 3
x x2
2
2 1 03 2 3 12 0
− − >
− −= >( ) ( )
( )True
x x2
2
2 1 00 2 0 1
1 0
− − >
− −= − >( ) ( )
( )False
x x2
2
2 1 01 2 1 12 0
− − >
− − − −= >( ) ( )
( )True
Higher Level, Educate.ie Sample 1, Paper 1 5
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 3 (25 marks)
lim lim( )
lim( )n n
nn
n
nn
nn→∞ →∞ →∞+
=+
=+
=2
3 423
23
234 4
Question 3 (a) (i)
Question 3 (a) (ii) Question 3 (a) (iii)
Question 3 (b) (i)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
[You can use the technique shown for finding the limit or you can find the limit by inspection.]
Terms of a geometric sequence: a ar ar ar arn, , , ,............,2 3 1−
1. Prove true for n = 1: S a rr
a1
111
=−−
=( )
[Therefore, true for n = 1.]
2. Assume true for n = k: Assume S a ar ar a rrk
kk
= + + + =−−
−............. ( )1 11
3. Prove true for n = k + 1: Prove S a ar ar ar a rrk
k kk
+−
+
= + + + + =−−1
111
1............. ( )
Proof:
( ............. ) ( )
(
a ar ar ar a rr
ar
a r
k kk
k
k
+ + + + =−−
+
=−
−1 11
1 )) ( )
( )
+ −−
=− + −
−
=−−
+
+
ar rr
a ar ar arr
a rr
k k k k
k
11 1
11
1
1
lim ,n
nr r→∞
= <0 1 lim ,n
nr r→∞
= ∞ >1
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
lim ( ) limn
n
n
n
→∞ →∞= = ∞
13
2 13
2lim limn
n
n
n
→∞ →∞
=
= × =
2 13
2 13
2 0 2
lim ,n
nr r→∞
= <0 1lim lim ( ) lim( ) ( limn n n
n
n
n
n
nS a rr
ar
r ar
r→∞ →∞ →∞ →∞
=−−
=−
− =−
−11 1
11
1 ))
( )=−
− =−
ar
ar1
1 01
Question 3 (b) (ii)
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
log log ( )
log ( )
( ) ( )
2 2
2
2 4 4 2
2
4 4
4 4
4 2 2 2 44 4
12
x x
x x
x xx x
+ + =
+ =
+ = = = =
+ − ==
=− ± − −
=− ± +
=− ±
=− ±
= − ±
>
0
4 4 4 1 42 1
4 16 162
4 322
4 4 22
2 2 2
0
2
x
x
( ) ( )( )( )
⇒⇒ = −x 2 2 2
Question 2 (c) (i)
x b b aca
=− ± −2 4
2
x xx x
2
2
2 12 1 0
− >
− − >
x x
x
2
2
2 1 0
2 2 4 1 12 1
2 4 42
2 82
2 2 22
1 2
− − =
=− − ± − − −
=± +
=±
=±
= ±
( ) ( ) ( )( )( )
x x x< − > + ∈1 2 1 2, , �
Question 2 (c) (ii)
[Solve the equality using the quadratic formula.]
SoLutionS:
Carry out the region test, or whatever test you use, to locate the regions that satisfy the inequality:
1 2+1 2−
ª 2 41.≈ −0 41.
−1 0 3
x x2
2
2 1 03 2 3 12 0
− − >
− −= >( ) ( )
( )True
x x2
2
2 1 00 2 0 1
1 0
− − >
− −= − >( ) ( )
( )False
x x2
2
2 1 01 2 1 12 0
− − >
− − − −= >( ) ( )
( )True
Sample 1
Paper 1
6 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
A
x
yB
′ = ⇒ + − =∴ = −f x x xx( ) ( )( )
,0 6 2 1 0
2 1
f x x xf A
( ) ( ) ( )( ) ( ) ( ( )) ( , )
= + −
− = − + − − = ⇒ −
2 5 22 2 2 5 2 2 0 2 0
2
2 is the locaal minimum.is the locf B( ) ( ) ( ( )) ( )( ) ( , )1 1 2 5 2 1 9 3 27 1 272= + − = = ⇒ aal maximum.
′′ = ⇒ − − =∴ = −
= + −
− = − + −
f x xx
f x x xf
( )
( ) ( ) ( )( ) ( ) (
0 12 6 0
2 5 22 5
12
2
12
12
2 22
5 16
12
32
2
94
272
12
272
( ))
( ) ( )( )( )
( , )
−
= +
= =
∴ −C is point of infleection.
C
x
yB
A
Question 5 (b)
f x x xf x x x x
x x
( ) ( ) ( )( ) ( ) ( ) ( ) ( )
( )[ (
= + −
′ = + − + − += + −
2 5 22 2 5 2 2 2
2 2
2
2 1
++ + −= + − − + −= + − += + −
′′
2 5 22 2 2 5 22 2 3 36 2 1
) ( )]( )[ ]( )[ ]( )( )
xx x xx xx x
ff x x xx xxx
( ) {( )( ) ( )( )}{ }{ }
( )
= + − + −= − − + −= − −= − +
6 2 1 1 16 2 16 2 1
6 2 1
to find turning pointS (tp):
Put dydx
f x= ′ =( ) 0 and solve for x.
d ydx
d ydx
2
2
2
2
0
0
< ⇒
> ⇒
TP
TP
Local Maximum
Local Minimum
′′ − = − − = > ⇒′′ = − = − > ⇒
ff
( ) ( )( ) ( )
2 6 3 18 01 6 3 18 0
Local MinimumLocal Maxximum
to find point of infLeCtion:
Put d ydx
f x2
2 0= ′′ =( ) and solve for x.
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 3 (c)
a r= =
231000
1100
,
Question 4 (25 marks)
kx x bx x x kxkx x bx x x kxk
3 2
3 2 2
6 6 1 3 26 6 2 3 2
− + − = + − +
− + − = − − +
( )( )( )( )( )
xx x bx kx x kx x kxkx x bx kx k x
3 2 3 2 2
3 2 3
6 6 2 2 4 3 66 6 2 2
− + − = + − − − −
− + − = + −( ) 22 4 3 6+ − − −( )k x
− = −=
∴ =
6 2 22 8
4
kkk
b kb= − −= − − = −
4 34 3 4 16( )
( )( )( ), ,
x x xx+ − + =
∴ = − −1 3 4 2 0
1 312
xx
xx
x x
x x xx x x
+>
++ > +
+ − + >+ − + >
12
11 2 1
1 2 1 01 2 1 0
2 2
2
( ) ( )
( ) ( )( )[ ( )](xx x xx x+ − − >+ − − >
1 2 2 01 2 0)[ ]
( )[ ]
( )( ),
x xx+ − − =
∴ = − −1 2 0
2 1
Question 4 (a)
Question 4 (b)
[A cubic equation equals a linear factor by a linear factor by a linear factor.The coefficients of x in each linear factor must multiply together to give k and the constants in each linear factor must multiply together to give −6. Find k and b by lining up the coefficients.]
[Multiply across by (x + 1)2. This is a positive value and so will not reverse the inequality.]
Solve the equality:
SoLutionS:
Carry out the region test, or whatever test you use, to locate the regions that satisfy the inequality:
−20
−1−3
( )( )( )( ) ( )x x+ − − >− >
1 2 02 1 0 False
− 32
( )( )( )( ) ( )x x+ − − >− >1 2 0
1 2 0 False( )( )( )( ) ( )x x+ − − >− − >
1 2 001
212 True
− < < − ∈2 1x x, �
0 523 0 5232323 12
231000
23100 000
. . ....... ..........⋅ ⋅
= = + + +
= +−
= +
= +
=
12 11212
23990
259495
231000
1100
231000
99100
Higher Level, Educate.ie Sample 1, Paper 1 7
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
A
x
yB
′ = ⇒ + − =∴ = −f x x xx( ) ( )( )
,0 6 2 1 0
2 1
f x x xf A
( ) ( ) ( )( ) ( ) ( ( )) ( , )
= + −
− = − + − − = ⇒ −
2 5 22 2 2 5 2 2 0 2 0
2
2 is the locaal minimum.is the locf B( ) ( ) ( ( )) ( )( ) ( , )1 1 2 5 2 1 9 3 27 1 272= + − = = ⇒ aal maximum.
′′ = ⇒ − − =∴ = −
= + −
− = − + −
f x xx
f x x xf
( )
( ) ( ) ( )( ) ( ) (
0 12 6 0
2 5 22 5
12
2
12
12
2 22
5 16
12
32
2
94
272
12
272
( ))
( ) ( )( )( )
( , )
−
= +
= =
∴ −C is point of infleection.
C
x
yB
A
Question 5 (b)
f x x xf x x x x
x x
( ) ( ) ( )( ) ( ) ( ) ( ) ( )
( )[ (
= + −
′ = + − + − += + −
2 5 22 2 5 2 2 2
2 2
2
2 1
++ + −= + − − + −= + − += + −
′′
2 5 22 2 2 5 22 2 3 36 2 1
) ( )]( )[ ]( )[ ]( )( )
xx x xx xx x
ff x x xx xxx
( ) {( )( ) ( )( )}{ }{ }
( )
= + − + −= − − + −= − −= − +
6 2 1 1 16 2 16 2 1
6 2 1
to find turning pointS (tp):
Put dydx
f x= ′ =( ) 0 and solve for x.
d ydx
d ydx
2
2
2
2
0
0
< ⇒
> ⇒
TP
TP
Local Maximum
Local Minimum
′′ − = − − = > ⇒′′ = − = − > ⇒
ff
( ) ( )( ) ( )
2 6 3 18 01 6 3 18 0
Local MinimumLocal Maxximum
to find point of infLeCtion:
Put d ydx
f x2
2 0= ′′ =( ) and solve for x.
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 3 (c)
a r= =
231000
1100
,
Question 4 (25 marks)
kx x bx x x kxkx x bx x x kxk
3 2
3 2 2
6 6 1 3 26 6 2 3 2
− + − = + − +
− + − = − − +
( )( )( )( )( )
xx x bx kx x kx x kxkx x bx kx k x
3 2 3 2 2
3 2 3
6 6 2 2 4 3 66 6 2 2
− + − = + − − − −
− + − = + −( ) 22 4 3 6+ − − −( )k x
− = −=
∴ =
6 2 22 8
4
kkk
b kb= − −= − − = −
4 34 3 4 16( )
( )( )( ), ,
x x xx+ − + =
∴ = − −1 3 4 2 0
1 312
xx
xx
x x
x x xx x x
+>
++ > +
+ − + >+ − + >
12
11 2 1
1 2 1 01 2 1 0
2 2
2
( ) ( )
( ) ( )( )[ ( )](xx x xx x+ − − >+ − − >
1 2 2 01 2 0)[ ]
( )[ ]
( )( ),
x xx+ − − =
∴ = − −1 2 0
2 1
Question 4 (a)
Question 4 (b)
[A cubic equation equals a linear factor by a linear factor by a linear factor.The coefficients of x in each linear factor must multiply together to give k and the constants in each linear factor must multiply together to give −6. Find k and b by lining up the coefficients.]
[Multiply across by (x + 1)2. This is a positive value and so will not reverse the inequality.]
Solve the equality:
SoLutionS:
Carry out the region test, or whatever test you use, to locate the regions that satisfy the inequality:
−20
−1−3
( )( )( )( ) ( )x x+ − − >− >
1 2 02 1 0 False
− 32
( )( )( )( ) ( )x x+ − − >− >1 2 0
1 2 0 False( )( )( )( ) ( )x x+ − − >− − >
1 2 001
212 True
− < < − ∈2 1x x, �
0 523 0 5232323 12
231000
23100 000
. . ....... ..........⋅ ⋅
= = + + +
= +−
= +
= +
=
12 11212
23990
259495
231000
1100
231000
99100
Sample 1
Paper 1
8 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
′ = − +
= ′ = − +
= − + +∫ ∫
f x x x
f x f x dx x x dx
x x x c
f
( )
( ) ( ) ( )
( )
9 4 5
9 4 5
3 2 5
1
2
2
3 2
==
= − + + =− + + =
∴ = −
∴ = − +
11 3 1 2 1 5 1 1
3 2 5 15
3 2 5
3 2
3 2
f cc
cf x x x x
( ) ( ) ( ) ( )
( ) −−5
Question 6 (b)
Question 7 (50 marks)
Q aet Q ae at Q a
a ae
e
bt
b
b
=
= = == =
∴ =
=
05730
0
12
12
5730
12
5730
::
( )
(
years
))
ln( ) ( )ln
ln
12
1
57302 5730
25730
=
− =
∴ = −
−
bb
b yr
a is the initial amount of Carbon-14
Qa
e= = =−
ln
. . %2
57302000
0 785 78 5
Question 7 (a)
Question 7 (b)
Question 7 (c) (i)
[At t = 0 years the amount of Carbon-14 present is a. After a half-life of 5730 years, the amount of Carbon-14 present will fall by a half of a.]
[Q divided by a (the initial amount) will give you the fraction of Carbon-14 present at any time.]
Q ae dQdt
abe
dQdtdQdt
abe
bt bt
t
t
= ⇒ =
==
=
−
4000
1000
25ln7730
4000
25730
1000
25730
4000
−
−
−=
abe
e
eln
ln
lnn
ln
.25730
1000
25730
30000 696
−
= =e
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
m x yy xy xy
= = −
− = +
− = +
− =
272 1 1
12
272
272
272
12
272
272
274
4 54
, ( , ) ( , )( )
554 2754 4 81 0
xx y
+− + =
Question 5 (c) Question 5 (d)
A x x dx
x x x dx
x x
= + −
= + + −
= − − +
−
−
∫
∫
(( ) ( ))
(( )( ))
(
2 5 2
4 4 5 2
2 3 1
2
2
0
2
2
0
3 2 22 20
24
33
122
20
6 2
2
0
4 3 2
2
0
12
4 3 2
x dx
x x x x
x x x
+
= − − + +
= − − + +
−
−
∫ )
00
0 2 2 6 2 20 28 8 24 40
16
2
0
12
4 3 2
x = − − − − − + − + −
= + − − +=
−
{ ( ) ( ) ( ) ( )}
Question 6 (25 marks)Question 6 (a) (i)
sin
( cos )
( sin )
2
12
12
12
1 2
2
x dx
x dx
x x c
∫∫= −
= − +
3
4 1
2
0
2
32
20
2
32
2 2 0
32
2 0
32
2
e dx
e
e e
e e
x
x
ln
ln
ln
ln
[ ]
( )
( )( )
∫=
= −
= −
= −
= 992
x x x x3 21 1 1+ = + − +( )( )
xx
dx
x x xx
dx
x x dx
x x x c
3
2
2
13
3 12
2
111 1
1
1
++
=+ − +
+
= − +
= − + +
∫
∫
∫
( )( )( )
( )
2
2
2 22
22
2 2
0
1
0
1
0
1
1 0
12
12
12
12
x
x
x
dx
dx
∫
∫=
=×
= −
=
ln
ln{ }( ) ( )
222
2 1ln
( )−
Question 6 (a) (ii)
Question 6 (a) (iii)
Question 6 (a) (iv)
Question 6 (a) (v)
xxdx
xxdx
x x dx
x x
+
= +
= +
= +
=
∫
∫
∫ −
1
1
2
1
9
1
9
1
9
23 1
9
12
12
32
12
( )
[ ]
{223
23
23
23
9 2 9 1 2 127 2 3 1 2 1
1
32
12
32
12( ) ( ) } { ( ) ( ) }
( ) ( ) ( ) ( )+ − +
= + − −
= 88 6 223
643
+ − −
=
Higher Level, Educate.ie Sample 1, Paper 1 9
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
′ = − +
= ′ = − +
= − + +∫ ∫
f x x x
f x f x dx x x dx
x x x c
f
( )
( ) ( ) ( )
( )
9 4 5
9 4 5
3 2 5
1
2
2
3 2
==
= − + + =− + + =
∴ = −
∴ = − +
11 3 1 2 1 5 1 1
3 2 5 15
3 2 5
3 2
3 2
f cc
cf x x x x
( ) ( ) ( ) ( )
( ) −−5
Question 6 (b)
Question 7 (50 marks)
Q aet Q ae at Q a
a ae
e
bt
b
b
=
= = == =
∴ =
=
05730
0
12
12
5730
12
5730
::
( )
(
years
))
ln( ) ( )ln
ln
12
1
57302 5730
25730
=
− =
∴ = −
−
bb
b yr
a is the initial amount of Carbon-14
Qa
e= = =−
ln
. . %2
57302000
0 785 78 5
Question 7 (a)
Question 7 (b)
Question 7 (c) (i)
[At t = 0 years the amount of Carbon-14 present is a. After a half-life of 5730 years, the amount of Carbon-14 present will fall by a half of a.]
[Q divided by a (the initial amount) will give you the fraction of Carbon-14 present at any time.]
Q ae dQdt
abe
dQdtdQdt
abe
bt bt
t
t
= ⇒ =
==
=
−
4000
1000
25ln7730
4000
25730
1000
25730
4000
−
−
−=
abe
e
eln
ln
lnn
ln
.25730
1000
25730
30000 696
−
= =e
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
m x yy xy xy
= = −
− = +
− = +
− =
272 1 1
12
272
272
272
12
272
272
274
4 54
, ( , ) ( , )( )
554 2754 4 81 0
xx y
+− + =
Question 5 (c) Question 5 (d)
A x x dx
x x x dx
x x
= + −
= + + −
= − − +
−
−
∫
∫
(( ) ( ))
(( )( ))
(
2 5 2
4 4 5 2
2 3 1
2
2
0
2
2
0
3 2 22 20
24
33
122
20
6 2
2
0
4 3 2
2
0
12
4 3 2
x dx
x x x x
x x x
+
= − − + +
= − − + +
−
−
∫ )
00
0 2 2 6 2 20 28 8 24 40
16
2
0
12
4 3 2
x = − − − − − + − + −
= + − − +=
−
{ ( ) ( ) ( ) ( )}
Question 6 (25 marks)Question 6 (a) (i)
sin
( cos )
( sin )
2
12
12
12
1 2
2
x dx
x dx
x x c
∫∫= −
= − +
3
4 1
2
0
2
32
20
2
32
2 2 0
32
2 0
32
2
e dx
e
e e
e e
x
x
ln
ln
ln
ln
[ ]
( )
( )( )
∫=
= −
= −
= −
= 992
x x x x3 21 1 1+ = + − +( )( )
xx
dx
x x xx
dx
x x dx
x x x c
3
2
2
13
3 12
2
111 1
1
1
++
=+ − +
+
= − +
= − + +
∫
∫
∫
( )( )( )
( )
2
2
2 22
22
2 2
0
1
0
1
0
1
1 0
12
12
12
12
x
x
x
dx
dx
∫
∫=
=×
= −
=
ln
ln{ }( ) ( )
222
2 1ln
( )−
Question 6 (a) (ii)
Question 6 (a) (iii)
Question 6 (a) (iv)
Question 6 (a) (v)
xxdx
xxdx
x x dx
x x
+
= +
= +
= +
=
∫
∫
∫ −
1
1
2
1
9
1
9
1
9
23 1
9
12
12
32
12
( )
[ ]
{223
23
23
23
9 2 9 1 2 127 2 3 1 2 1
1
32
12
32
12( ) ( ) } { ( ) ( ) }
( ) ( ) ( ) ( )+ − +
= + − −
= 88 6 223
643
+ − −
=
Sample 1
Paper 1
10 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Q aeQ Q aeQ Q ae
Q aeQ ae
bt
bt
bt
bt
bt
=
− =
+ =
=
=
0 050 05
0 951 050 95
1
2
1
2
.
.... QQQ
ee
e
b t t
t t
bt
btb t t
1 050 951 05
1
2
1 2
1 2
1 2
.
ln ..
( )
(
( )= =
∴
= −
−
−
))ln .
.ln .
.ln
=
=
−
=
0 951 05
0 951 05
25730
827b
yearrs
Question 7 (f)Q aeQ aeQ a eQ bt a y mx c
bt
bt
bt
=
=
= += + → = +
ln ln( )ln ln ln( )ln ln ( )b is the slope of the graph and ln a is the y-intercept.
b
b
=−−
= − ×
= − = − ×
− −
−
1 08 0 842500 4500
1 2 10
25730
1 21 10
4 1
4
. . .
ln .
year
yeear−1
Question 7 (e)
ln . ..a a e= ⇒ = =1 38 3 9751 38 mg
Question 8 (50 marks)
x pp x
p xx
x
= −= −
= − ≥∴ ≥≤
20 000 100100 20 000
200 0 01 020 000
20 000
.
C xdCdx
= +
= =
120 000 40
40 constant
It costs 40 to produce one more phone at any level of production.
R x pp xR x x x x
= ×= −
∴ = − = −
200 0 01200 0 01 200 0 01 2
.( . ) .
R x xx x
x x
= − ≥
− ≥− ≥
200 0 01 020 000 0
20 000 0
2
2
.
( )
Question 8 (a) Question 8 (b) (i)
Question 8 (b) (ii) Question 8 (c) (i)
Question 8 (c) (ii) Question 8 (d)
Solve the equality:
SoLution: 0 20 000£ £x
R x xdRdx
x
dRdx
x
xx
= −
= −
= ⇒ − =
=∴ =
200 0 01
200 0 02
0 200 0 02 0
200 0 021
2.
.
.
.00 000200 10 000 0 01 10 000 1 000 0002RMax. = − =( ) . ( )
x xx
( ),
20 000 00 20 000
− =∴ =
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Qa
e
t
t
t= =
= −
∴ = −
−
0 93
0 93 25730
5730
25730.
ln( . ) ln
ln
ln
(( . )ln
0 932
600= years
Question 7 (c) (ii)
t (years) 1000 2000 3000 4000 5000 6000
Q (mg) 3.54 3.14 2.78 2.47 2.18 1.94
ln Q 1.26 1.14 1.02 0.90 0.78 0.66
Question 7 (d) (i)
1000 2000 3000 4000 5000 6000
t (years)
0
0.40
0.20
0.60
1.20
ln Q
0.80
1.00
1.40
(4500, 0.84)
(2500, 1.08)
Question 7 (d) (ii)
Higher Level, Educate.ie Sample 1, Paper 1 11
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Q aeQ Q aeQ Q ae
Q aeQ ae
bt
bt
bt
bt
bt
=
− =
+ =
=
=
0 050 05
0 951 050 95
1
2
1
2
.
.... QQQ
ee
e
b t t
t t
bt
btb t t
1 050 951 05
1
2
1 2
1 2
1 2
.
ln ..
( )
(
( )= =
∴
= −
−
−
))ln .
.ln .
.ln
=
=
−
=
0 951 05
0 951 05
25730
827b
yearrs
Question 7 (f)Q aeQ aeQ a eQ bt a y mx c
bt
bt
bt
=
=
= += + → = +
ln ln( )ln ln ln( )ln ln ( )b is the slope of the graph and ln a is the y-intercept.
b
b
=−−
= − ×
= − = − ×
− −
−
1 08 0 842500 4500
1 2 10
25730
1 21 10
4 1
4
. . .
ln .
year
yeear−1
Question 7 (e)
ln . ..a a e= ⇒ = =1 38 3 9751 38 mg
Question 8 (50 marks)
x pp x
p xx
x
= −= −
= − ≥∴ ≥≤
20 000 100100 20 000
200 0 01 020 000
20 000
.
C xdCdx
= +
= =
120 000 40
40 constant
It costs 40 to produce one more phone at any level of production.
R x pp xR x x x x
= ×= −
∴ = − = −
200 0 01200 0 01 200 0 01 2
.( . ) .
R x xx x
x x
= − ≥
− ≥− ≥
200 0 01 020 000 0
20 000 0
2
2
.
( )
Question 8 (a) Question 8 (b) (i)
Question 8 (b) (ii) Question 8 (c) (i)
Question 8 (c) (ii) Question 8 (d)
Solve the equality:
SoLution: 0 20 000£ £x
R x xdRdx
x
dRdx
x
xx
= −
= −
= ⇒ − =
=∴ =
200 0 01
200 0 02
0 200 0 02 0
200 0 021
2.
.
.
.00 000200 10 000 0 01 10 000 1 000 0002RMax. = − =( ) . ( )
x xx
( ),
20 000 00 20 000
− =∴ =
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Qa
e
t
t
t= =
= −
∴ = −
−
0 93
0 93 25730
5730
25730.
ln( . ) ln
ln
ln
(( . )ln
0 932
600= years
Question 7 (c) (ii)
t (years) 1000 2000 3000 4000 5000 6000
Q (mg) 3.54 3.14 2.78 2.47 2.18 1.94
ln Q 1.26 1.14 1.02 0.90 0.78 0.66
Question 7 (d) (i)
1000 2000 3000 4000 5000 6000
t (years)
0
0.40
0.20
0.60
1.20
ln Q
0.80
1.00
1.40
(4500, 0.84)
(2500, 1.08)
Question 7 (d) (ii)
Sample 1
Paper 1
12 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 8 (g)
x b b aca
=− ± −2 4
2
Breakeven points from graph: (780, 145 000), (15 200, 720 000)
CaLCuLuS:
grapH: The maximum profit is the greatest distance between the R and C graphs.PMax. = 960 000 − 440 000 = 520 000
xp xp
== −
∴ = − =
8 000200 0 01
200 0 01 8000 120
,.
. ( )
Question 8 (h) (i)
Question 8 (h) (ii)
R Cx x x
x x
x
=
− = +
− + =
=− − ±
200 0 01 120 000 4016 000 12 000 000 0
16 000
2
2
.
( ) (−− −
∴ =
16 000 4 12 000 0002
789 15 211
2) ( )
,x
P R C x x xx x
dPdx
= − = − − −
= − + −
= −
200 0 01 120 000 400 01 160 120 000
0 02
2
2
..
. xx
dPdx
x
xx
P
+
= ⇒ − + =
=∴ =
= −
160
0 0 02 160 0
160 0 028000
0 01 8000
.
.
. ( )Max.22 160 8000 120 000 520 000+ − =( )
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
x R () C ()
0 0 120 000
4000 640 000 280 000
8000 960 000 440 000
12 000 960 000 600 000
16 000 640 000 760 000
20 000 0 920 000
Question 8 (e) (i)
20000180001200010000
(15200, 720000)
60004000
600 000
1600014000 x0
500 000
800 000
700 000
200 000
100 000
400 000
300 000
1 000 000
900 000
C
R
(euro)
(euro)
2000
Profit Loss
8000
(780, 145000)
Maximum
Profit
960 000
440 000
Question 8 (e) (ii)
Question 8 (f) (See graph above)
Higher Level, Educate.ie Sample 1, Paper 1 13
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 8 (g)
x b b aca
=− ± −2 4
2
Breakeven points from graph: (780, 145 000), (15 200, 720 000)
CaLCuLuS:
grapH: The maximum profit is the greatest distance between the R and C graphs.PMax. = 960 000 − 440 000 = 520 000
xp xp
== −
∴ = − =
8 000200 0 01
200 0 01 8000 120
,.
. ( )
Question 8 (h) (i)
Question 8 (h) (ii)
R Cx x x
x x
x
=
− = +
− + =
=− − ±
200 0 01 120 000 4016 000 12 000 000 0
16 000
2
2
.
( ) (−− −
∴ =
16 000 4 12 000 0002
789 15 211
2) ( )
,x
P R C x x xx x
dPdx
= − = − − −
= − + −
= −
200 0 01 120 000 400 01 160 120 000
0 02
2
2
..
. xx
dPdx
x
xx
P
+
= ⇒ − + =
=∴ =
= −
160
0 0 02 160 0
160 0 028000
0 01 8000
.
.
. ( )Max.22 160 8000 120 000 520 000+ − =( )
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
x R () C ()
0 0 120 000
4000 640 000 280 000
8000 960 000 440 000
12 000 960 000 600 000
16 000 640 000 760 000
20 000 0 920 000
Question 8 (e) (i)
20000180001200010000
(15200, 720000)
60004000
600 000
1600014000 x0
500 000
800 000
700 000
200 000
100 000
400 000
300 000
1 000 000
900 000
C
R
(euro)
(euro)
2000
Profit Loss
8000
(780, 145000)
Maximum
Profit
960 000
440 000
Question 8 (e) (ii)
Question 8 (f) (See graph above)
Sample 1
Paper 1
14 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
t (days) 0p6
p3
p2
23p 5
6p
p 1000 1000e 10001000
e1000 1000e
p 1000 2700 1000 370 1000 2700
2000
3
3000
4000
�
Period
1000
0
6
�
2
�
3
2�
6
5�
t (days)
p
Range
Question 9 (f) (i)
Period days= =23
2 1p .
Question 9 (f) (ii)
Range =
1000 1000e
e,
This represents the population in a cycle from its maximum to minimum values.
This is the time for the population to return to its original value at any point in the cycle.
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 9 (50 marks)
dpdt
mp mt
dpp
m mt dt
p m mtm
c
p mt ct p N
=
=
= +
= += =
Ú Ú
cos
cos
ln sin
ln sin, :0 lln sin ln
ln sin ln
ln sin
sin
N c c Np mt NpN
mt
p Ne mt
= + fi == +
ÊËÁ
ˆ¯̃
=
=
0
p Nep N N Ne
tt
t
t
== =
== = =-
sin
sin:sin ln
sin (ln ) .
3
3
13
1
2 23 2
2 0 255 days 3368 minutes
dpdt
kp
dpp
k dt
p kt ct p N N c c Np kt N
=
=
= += = = + fi == +
Ú Úln
, : ln lnln lnl
At 0 0
nn ln
ln
p N ktpN
kt
pN
e
p Ne
kt
kt
- =
ÊËÁ
ˆ¯̃
=
=
\ =
p Nep N N Neet
t
t
t
t
== fi ==
=
= = =
3
3
3
2 22
2 32
30 231 333
lnln . days minutes
cos sinmxdx mx cmÚ = +1
Question 9 (a)
[Separate the variables.]
Question 9 (b)
Question 9 (c)
Question 9 (d)
Question 9 (e)
Question 9 (f)
p et p e e
t p e
t=
= = = =
= =
10000 1000 1000 1000
61000
3
3 0 0
3
sin
sin ( )
sin
:
:p (( )
sin ( ):
:
16
13
1000 2700
31000 1000 1000
21
3 0
p
pp
p
= ≈
= = = =
= =
e
t p e e
t p 0000 1000 1000 370
23
1000 100
3 1
3
12
23
e ee
t p e
sin ( )
sin ( ):
p
pp
= = ≈
= = =
−
00 1000
56
1000 1000 2700
0
3 56
e
t p e e
=
= = = ≈p p: sin ( )
Higher Level, Educate.ie Sample 1, Paper 1 15
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
t (days) 0p6
p3
p2
23p 5
6p
p 1000 1000e 10001000
e1000 1000e
p 1000 2700 1000 370 1000 2700
2000
3
3000
4000
�
Period
1000
0
6
�
2
�
3
2�
6
5�
t (days)
p
Range
Question 9 (f) (i)
Period days= =23
2 1p .
Question 9 (f) (ii)
Range =
1000 1000e
e,
This represents the population in a cycle from its maximum to minimum values.
This is the time for the population to return to its original value at any point in the cycle.
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
Question 9 (50 marks)
dpdt
mp mt
dpp
m mt dt
p m mtm
c
p mt ct p N
=
=
= +
= += =
Ú Ú
cos
cos
ln sin
ln sin, :0 lln sin ln
ln sin ln
ln sin
sin
N c c Np mt NpN
mt
p Ne mt
= + fi == +
ÊËÁ
ˆ¯̃
=
=
0
p Nep N N Ne
tt
t
t
== =
== = =-
sin
sin:sin ln
sin (ln ) .
3
3
13
1
2 23 2
2 0 255 days 3368 minutes
dpdt
kp
dpp
k dt
p kt ct p N N c c Np kt N
=
=
= += = = + fi == +
Ú Úln
, : ln lnln lnl
At 0 0
nn ln
ln
p N ktpN
kt
pN
e
p Ne
kt
kt
- =
ÊËÁ
ˆ¯̃
=
=
\ =
p Nep N N Neet
t
t
t
t
== fi ==
=
= = =
3
3
3
2 22
2 32
30 231 333
lnln . days minutes
cos sinmxdx mx cmÚ = +1
Question 9 (a)
[Separate the variables.]
Question 9 (b)
Question 9 (c)
Question 9 (d)
Question 9 (e)
Question 9 (f)
p et p e e
t p e
t=
= = = =
= =
10000 1000 1000 1000
61000
3
3 0 0
3
sin
sin ( )
sin
:
:p (( )
sin ( ):
:
16
13
1000 2700
31000 1000 1000
21
3 0
p
pp
p
= ≈
= = = =
= =
e
t p e e
t p 0000 1000 1000 370
23
1000 100
3 1
3
12
23
e ee
t p e
sin ( )
sin ( ):
p
pp
= = ≈
= = =
−
00 1000
56
1000 1000 2700
0
3 56
e
t p e e
=
= = = ≈p p: sin ( )
Sample 1
Paper 1
16 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
s x yx y
r
s x y y
12 2
2 2
22 2
9 09
0 0 3
6 8 0
:
( , ),
:(
+ − =
+ ==
+ − + =−
Centre
Centre gg f
r g f c
, ) ( , )− =
= + − = + − = =
0 3
0 9 8 1 12 2
( ) ( ) ( ) ( ) ( )
( ) ( ) ( )
h k r h k r
h k r h
− + − = + ⇒ + − = +
− + − = + ⇒
0 3 1 3 1
0 0 3
2 2 2 2 2
2 2 2 ++ = +
− − = + − +
− + − − = + + +
k r
k k r r
k k k k r r
2 2
2 2 2 2
3
3 1 3
3 3 1 3
( )
( ) ( ) ( )
( )( ) ( )(( )( )( ) ( )( )
r rk rk rr k
+ − −− − = + −
− + = − −+ =
1 32 3 3 2 4 26 9 4 8
4 17 6
Question 2 (25 marks)
Question 2 (a)
Question 2 (b)
a b a b a b2 2− = − +( )( )
a b a b a b2 2− = − +( )( )
(0, 0)
r1
r
3
(0, 3)( , )h k
s
s1
s2
h k r
r k r k
h k k
h k k
2 2 2
2 22
2 2
3
4 17 6 6 174
6 174
3
6
+ = +
+ = ⇒ =−
+ =−
+
+ =
( )
−− +
=
−
=−
−
= − −
17 124
6 54
6 516
16 6 5 16
2 2
22
2
2 2
k
h k k
h k
( )
( ) kkh k k k kh k kh k
2
2
2
2
16 6 5 4 6 5 416 10 5 2 5
16 5 2 1
= − + − −
= − −
∴ = −
( )( )( )( )
( )(22 5k − )
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
A(5, 10)
B( 3, 4)�
C( 1, 2)� �
A B
m
( , ), ( , )
, ( , )
5 10 3 45 3
210 4
21 7
4 103 5
−
=− +
=
=−
− −=
Mid-point
−−−
= ⇒ = −
− = − −
− = − −− = − +
⊥68
34
43
7 13 7 4 13 21 4 44
43
m
k y xy xy xx
: ( ) ( )( ) ( )
++ − =3 25 0y
A C
m
( , ), ( , )
, ( , )
5 10 1 25 1
210 2
22 4
2 101
− −
=− −
=
=− −− −
Mid-point
55126
2 12
4 22 4 1 22 8 2
12
=−−
= ⇒ = −
− = − −
− = − −− = − ++
⊥m
l y xy xy xx
: ( ) ( )( ) ( )
22 10 0y − =
4 3 25 02 10 0 4
4 3 25 04 8 40 0
5 15 0 3
x yx y
x yx y
y y
x
+ − =+ − = ×−
+ − =− − + =
− + = ⇒ =
( )
++ − =+ − =
∴ =
2 3 10 06 10 0
4
( )xx
Circumcentre D(4, 3)r AD= = − + − = + = =( ) ( )5 4 10 3 1 49 50 5 22 2
Equation of circumcircle: ( ) ( ) ( )( ) ( )x yx y− + − =
− + − =
4 3 504 3 50
2 2 2
2 2
Question 1 (25 marks)
sample paper 1: paper 2
Question 1 (a)
[Solve the equations simultaneously for k and l to find their point of intersection D.]
Question 1 (b)
17Higher Level, Educate.ie Sample 1, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
s x yx y
r
s x y y
12 2
2 2
22 2
9 09
0 0 3
6 8 0
:
( , ),
:(
+ − =
+ ==
+ − + =−
Centre
Centre gg f
r g f c
, ) ( , )− =
= + − = + − = =
0 3
0 9 8 1 12 2
( ) ( ) ( ) ( ) ( )
( ) ( ) ( )
h k r h k r
h k r h
− + − = + ⇒ + − = +
− + − = + ⇒
0 3 1 3 1
0 0 3
2 2 2 2 2
2 2 2 ++ = +
− − = + − +
− + − − = + + +
k r
k k r r
k k k k r r
2 2
2 2 2 2
3
3 1 3
3 3 1 3
( )
( ) ( ) ( )
( )( ) ( )(( )( )( ) ( )( )
r rk rk rr k
+ − −− − = + −
− + = − −+ =
1 32 3 3 2 4 26 9 4 8
4 17 6
Question 2 (25 marks)
Question 2 (a)
Question 2 (b)
a b a b a b2 2− = − +( )( )
a b a b a b2 2− = − +( )( )
(0, 0)
r1
r
3
(0, 3)( , )h k
s
s1
s2
h k r
r k r k
h k k
h k k
2 2 2
2 22
2 2
3
4 17 6 6 174
6 174
3
6
+ = +
+ = ⇒ =−
+ =−
+
+ =
( )
−− +
=
−
=−
−
= − −
17 124
6 54
6 516
16 6 5 16
2 2
22
2
2 2
k
h k k
h k
( )
( ) kkh k k k kh k kh k
2
2
2
2
16 6 5 4 6 5 416 10 5 2 5
16 5 2 1
= − + − −
= − −
∴ = −
( )( )( )( )
( )(22 5k − )
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
A(5, 10)
B( 3, 4)�
C( 1, 2)� �
A B
m
( , ), ( , )
, ( , )
5 10 3 45 3
210 4
21 7
4 103 5
−
=− +
=
=−
− −=
Mid-point
−−−
= ⇒ = −
− = − −
− = − −− = − +
⊥68
34
43
7 13 7 4 13 21 4 44
43
m
k y xy xy xx
: ( ) ( )( ) ( )
++ − =3 25 0y
A C
m
( , ), ( , )
, ( , )
5 10 1 25 1
210 2
22 4
2 101
− −
=− −
=
=− −− −
Mid-point
55126
2 12
4 22 4 1 22 8 2
12
=−−
= ⇒ = −
− = − −
− = − −− = − ++
⊥m
l y xy xy xx
: ( ) ( )( ) ( )
22 10 0y − =
4 3 25 02 10 0 4
4 3 25 04 8 40 0
5 15 0 3
x yx y
x yx y
y y
x
+ − =+ − = ×−
+ − =− − + =
− + = ⇒ =
( )
++ − =+ − =
∴ =
2 3 10 06 10 0
4
( )xx
Circumcentre D(4, 3)r AD= = − + − = + = =( ) ( )5 4 10 3 1 49 50 5 22 2
Equation of circumcircle: ( ) ( ) ( )( ) ( )x yx y− + − =
− + − =
4 3 504 3 50
2 2 2
2 2
Question 1 (25 marks)
sample paper 1: paper 2
Question 1 (a)
[Solve the equations simultaneously for k and l to find their point of intersection D.]
Question 1 (b)
Sample 1
Paper 2
18 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
z x
xx
= − =−
− = −∴ =
0 68 104
2 72 107 28
.
.. ( )Lower Quartile
Interquartile range = UQ − LQ = 12.72 − 7.28 = 5.44
146 µ = 10
68%
Standard deviation = 4Median = 10 x z
x z
x z
= =−
=
= =−
=
= =−
= −
10 10 104
0
14 14 104
1
6 6 104
1
:
:
:
The standard normal distribution has a mean of 0 and standard deviation of 1 and has the same shape and area distribution as the original normal distribution.
P z Z
z x
xx
( ) .
.
.. ( )
< =
∴ = =−
= −∴ =
0 75
0 68 104
2 72 1012 72 Upper Quartile
Question 4 (25 marks)
empiriCaL ruLe: In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
Question 4 (a) (i) Question 4 (a) (ii)
z x=
− µσ
Question 4 (b)
Question 4 (c) (i) Question 4 (c) (ii)
Question 4 (c) (iii)
UQ = Z
75%
zz Z=LQ = �Z
25%
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
AS
CT
xo –90 –60 –45 –30 0 30 45 60 90y –∞ –1.7 –1 –0.6 0 0.6 1 1.7 ∞
xo 105 120 135 150 180 210 225 240 270y –3.7 –1.7 –1 –0.6 0 0.6 1 1.7 –∞
�30o
�90o
5
0o
30o
60o
90o
270o
150o
240o
210o
180o
120o
4
3
�1
2
�5
�3
�2
�4
1
x
y
�60o
Yes, because each value of x only gives one value of y.
AS
CT
60o
tan tan ( )x x= ⇒ = =−3 3 601 o
Second quadrant: x = 180o − 60o = 120o
Fourth quadrant: x = 360o − 60o = 300o
Question 3 (25 marks)Question 3 (a) (i)
Question 3 (b) (i)
Question 3 (a) (ii)
tantan( )
tan
330360 3030
13
o
o o
o
= −
= −
= −
Question 3 (b) (ii)
Period = 180o (function repeats itself every 180o)Range = [ , ]−∞ ∞
Question 3 (b) (iii)
Question 3 (b) (iv)
19Higher Level, Educate.ie Sample 1, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
z x
xx
= − =−
− = −∴ =
0 68 104
2 72 107 28
.
.. ( )Lower Quartile
Interquartile range = UQ − LQ = 12.72 − 7.28 = 5.44
146 µ = 10
68%
Standard deviation = 4Median = 10 x z
x z
x z
= =−
=
= =−
=
= =−
= −
10 10 104
0
14 14 104
1
6 6 104
1
:
:
:
The standard normal distribution has a mean of 0 and standard deviation of 1 and has the same shape and area distribution as the original normal distribution.
P z Z
z x
xx
( ) .
.
.. ( )
< =
∴ = =−
= −∴ =
0 75
0 68 104
2 72 1012 72 Upper Quartile
Question 4 (25 marks)
empiriCaL ruLe: In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
Question 4 (a) (i) Question 4 (a) (ii)
z x=
− µσ
Question 4 (b)
Question 4 (c) (i) Question 4 (c) (ii)
Question 4 (c) (iii)
UQ = Z
75%
zz Z=LQ = �Z
25%
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
AS
CT
xo –90 –60 –45 –30 0 30 45 60 90y –∞ –1.7 –1 –0.6 0 0.6 1 1.7 ∞
xo 105 120 135 150 180 210 225 240 270y –3.7 –1.7 –1 –0.6 0 0.6 1 1.7 –∞
�30o
�90o
5
0o
30o
60o
90o
270o
150o
240o
210o
180o
120o
4
3
�1
2
�5
�3
�2
�4
1
x
y
�60o
Yes, because each value of x only gives one value of y.
AS
CT
60o
tan tan ( )x x= ⇒ = =−3 3 601 o
Second quadrant: x = 180o − 60o = 120o
Fourth quadrant: x = 360o − 60o = 300o
Question 3 (25 marks)Question 3 (a) (i)
Question 3 (b) (i)
Question 3 (a) (ii)
tantan( )
tan
330360 3030
13
o
o o
o
= −
= −
= −
Question 3 (b) (ii)
Period = 180o (function repeats itself every 180o)Range = [ , ]−∞ ∞
Question 3 (b) (iii)
Question 3 (b) (iv)
Sample 1
Paper 2
20 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
B
A D
C
G
F8 cm
12 cm
12
4 cm
4 cm
Question 6 (25 marks)
AD BC
BF FC
BF FC
= =
=
∴ = =
12
2
8 4
cm
cm, cm
Triangle FCD: A = =12
24 4 8( )( ) cm
Triangle AFD: A = =12
212 4 24( )( ) cm
Parallelogram ABCD: A = =( )( )12 4 48 2cmTriangle BFA: A = − − =48 8 24 16 2cm
Question 6 (a) Question 6 (b)
Question 6 (c)
AF AF
BG
BG
2 2 2
12
4 12 16 144 160 160 4 10
4 10 16
4 105
= + = + = ⇒ = =
=
∴ =
( )
cm
Question 7 (75 marks)
µσ
µ σµ σ
=== + = += − = −
12015
135 120 15 1105 120 15 1
empiriCaL ruLe: 68% of young adults have a blood pressure reading of between 105 mm of Hg and 135 mm of Hg.
µσ==
= =−
= −
= =−
=
12015
116 116 12015
0 27
123 123 12015
0 2
1 1
2 1
x z
x z
: .
: .
Question 7 (a) (i)
Question 7 (a) (ii)
z
z1= 0.27� z
2= 0.2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
9999 yx
Possibilities for arranging the numbers in ascending order:Median = +
=9 9
29
(ii) Mode = 9
(iii) Range cannot be worked out without knowing the values of x and y.
9, 9, 9, 9, x, yx, y, 9, 9, 9, 9x, 9, 9, 9, 9, yy, 9, 9, 9, 9, x9, 9, 9, 9, 9, 9
Mean = 9Therefore sum = 9 6 54× =x y+ = − =54 36 18Possibilities for x and y:x 1 2 3 4 5 6 7 8 9y 17 16 15 14 13 12 11 10 9
or
x 17 16 15 14 13 12 11 10 9y 1 2 3 4 5 6 7 8 9
Greatest range = [1, 17]R = 17 − 1 = 16
R x yx xy
= − =∴ = ⇒ =∴ =
62 24 12
6
Question 5 (25 marks)
Question 5 (a)
(i)
Question 5 (b)
Question 5 (c)
21Higher Level, Educate.ie Sample 1, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
B
A D
C
G
F8 cm
12 cm
12
4 cm
4 cm
Question 6 (25 marks)
AD BC
BF FC
BF FC
= =
=
∴ = =
12
2
8 4
cm
cm, cm
Triangle FCD: A = =12
24 4 8( )( ) cm
Triangle AFD: A = =12
212 4 24( )( ) cm
Parallelogram ABCD: A = =( )( )12 4 48 2cmTriangle BFA: A = − − =48 8 24 16 2cm
Question 6 (a) Question 6 (b)
Question 6 (c)
AF AF
BG
BG
2 2 2
12
4 12 16 144 160 160 4 10
4 10 16
4 105
= + = + = ⇒ = =
=
∴ =
( )
cm
Question 7 (75 marks)
µσ
µ σµ σ
=== + = += − = −
12015
135 120 15 1105 120 15 1
empiriCaL ruLe: 68% of young adults have a blood pressure reading of between 105 mm of Hg and 135 mm of Hg.
µσ==
= =−
= −
= =−
=
12015
116 116 12015
0 27
123 123 12015
0 2
1 1
2 1
x z
x z
: .
: .
Question 7 (a) (i)
Question 7 (a) (ii)
z
z1= 0.27� z
2= 0.2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
9999 yx
Possibilities for arranging the numbers in ascending order:Median = +
=9 9
29
(ii) Mode = 9
(iii) Range cannot be worked out without knowing the values of x and y.
9, 9, 9, 9, x, yx, y, 9, 9, 9, 9x, 9, 9, 9, 9, yy, 9, 9, 9, 9, x9, 9, 9, 9, 9, 9
Mean = 9Therefore sum = 9 6 54× =x y+ = − =54 36 18Possibilities for x and y:x 1 2 3 4 5 6 7 8 9y 17 16 15 14 13 12 11 10 9
or
x 17 16 15 14 13 12 11 10 9y 1 2 3 4 5 6 7 8 9
Greatest range = [1, 17]R = 17 − 1 = 16
R x yx xy
= − =∴ = ⇒ =∴ =
62 24 12
6
Question 5 (25 marks)
Question 5 (a)
(i)
Question 5 (b)
Question 5 (c)
Sample 1
Paper 2
22 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
BA
CD
F230 m
45o
230 m
230 m
230 m
45o
cos
cos
45230
230 45 115 2
o
o m
=
= =
FC
FC
F
E
C
149 m
115 2 m
EC = + =149 115 2 2212 2( ) m
Question 8 (a) (ii)
Question 8 (b)
Question 8 (c)
h
A
x
16.3o
100 m
20o
160o
3.7o
p
Question 8 (75 marks)Question 8 (a) (i)
1003 7 16 3
100 16 33 7
434 92
204
sin . sin .sin .
sin ..
sin
o
o
o
o
o
m
=
∴ = =
=
p
p
h334 92
434 92 20 148 75 149.
. sin .∴ = = ≈h o m
aA
bBsin sin
=
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
H
Sc
Start
S
Hc
H
Hc
0.9
0.1
0.4
0.6
0.2
0.8P S Hc c( ) .∩ = 0 72
P S Hc( ) .∩ = 0 18
P S H c( ) .∩ = 0 06
P S H( ) .∩ = 0 04Question 7 (d)
P P PP P zP
= −∞ − −∞ −= −∞ − >= −∞
( . ) ( . )( . ) ( . )(
to to to to
0 2 0 270 2 0 270.. ) { ( . )}
. .
.
2 1 0 270 5793 1 0 60640 1857
− − <= − +=
P z
From a sample of 100 people the number will be 100 0 1857× =. 18 or 19 people
Question 7 (b)(i) P(S) = 0.1(ii) P(H|S) = 0.4(iii) P(H|S
c) = 0.2
P S H P H SP H
( | ) ( )( )
=∩
Question 7 (c)
P H P S H P S Hc( ) ( ) ( ). ..
= ∩ + ∩= +=
0 04 0 180 22
P S H P S HP H
( | ) ( )( )
.
..=
∩= =
0 040 22
0 182
PPP
( ) .( ) .(
Having a strokeNot having a strokeAt le
==
0 1820 818
aast 2 out of 10 people will suffer a stroke2 out of
)(= −1 P 10 people will suffer a stroke)
{ ( . ) ( . )= −1 0 182 0 818100
0 10C ++=
101
1 90 182 0 8180 57
C ( . ) ( . ) }.
Question 7 (e) Question 7 (f)
Question 7 (g)
23Higher Level, Educate.ie Sample 1, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
BA
CD
F230 m
45o
230 m
230 m
230 m
45o
cos
cos
45230
230 45 115 2
o
o m
=
= =
FC
FC
F
E
C
149 m
115 2 m
EC = + =149 115 2 2212 2( ) m
Question 8 (a) (ii)
Question 8 (b)
Question 8 (c)
h
A
x
16.3o
100 m
20o
160o
3.7o
p
Question 8 (75 marks)Question 8 (a) (i)
1003 7 16 3
100 16 33 7
434 92
204
sin . sin .sin .
sin ..
sin
o
o
o
o
o
m
=
∴ = =
=
p
p
h334 92
434 92 20 148 75 149.
. sin .∴ = = ≈h o m
aA
bBsin sin
=
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
H
Sc
Start
S
Hc
H
Hc
0.9
0.1
0.4
0.6
0.2
0.8P S Hc c( ) .∩ = 0 72
P S Hc( ) .∩ = 0 18
P S H c( ) .∩ = 0 06
P S H( ) .∩ = 0 04Question 7 (d)
P P PP P zP
= −∞ − −∞ −= −∞ − >= −∞
( . ) ( . )( . ) ( . )(
to to to to
0 2 0 270 2 0 270.. ) { ( . )}
. .
.
2 1 0 270 5793 1 0 60640 1857
− − <= − +=
P z
From a sample of 100 people the number will be 100 0 1857× =. 18 or 19 people
Question 7 (b)(i) P(S) = 0.1(ii) P(H|S) = 0.4(iii) P(H|S
c) = 0.2
P S H P H SP H
( | ) ( )( )
=∩
Question 7 (c)
P H P S H P S Hc( ) ( ) ( ). ..
= ∩ + ∩= +=
0 04 0 180 22
P S H P S HP H
( | ) ( )( )
.
..=
∩= =
0 040 22
0 182
PPP
( ) .( ) .(
Having a strokeNot having a strokeAt le
==
0 1820 818
aast 2 out of 10 people will suffer a stroke2 out of
)(= −1 P 10 people will suffer a stroke)
{ ( . ) ( . )= −1 0 182 0 818100
0 10C ++=
101
1 90 182 0 8180 57
C ( . ) ( . ) }.
Question 7 (e) Question 7 (f)
Question 7 (g)
Sample 1
Paper 2
24 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
a
a
a
a
b
b
bb
b
x
bb
2
a
2
a
b
a x b x b a b a b a2 4
44
42
2 2 22 2 2
12
2 2
+ = ⇒ = − =
−= −
Area of 4 triangles:
230 m
221 m
115 m
221 m
115 m
188.7 m
Surface area: A a b a= − = − =4 230 4 221 230 86 8122 2 2 2 2( ) m
A
a b a a b a
= × × = × ×
= × − = −
4 2
2 4 4
12
12
2 2 2 2
( )base height base height
Area of a casing stone = (0.86 m)(0.86 m) = 0.7396 m2
Number of stones = ≈86 8120 7396
117 000.
Question 8 (e)
Question 8 (f) (i)
Question 8 (f) (ii)
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
188.7 m 230 m 188.7 m
230 m
221 m
115 m
221 m
115 m
x
115 221
221 115 188 7
2 2 2
2 2
+ =
= − =
x
x . m
Length of square =+
=2 188 7 230
5012 15( . ) . m
Question 8 (d)
25Higher Level, Educate.ie Sample 1, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
a
a
a
a
b
b
bb
b
x
bb
2
a
2
a
b
a x b x b a b a b a2 4
44
42
2 2 22 2 2
12
2 2
+ = ⇒ = − =
−= −
Area of 4 triangles:
230 m
221 m
115 m
221 m
115 m
188.7 m
Surface area: A a b a= − = − =4 230 4 221 230 86 8122 2 2 2 2( ) m
A
a b a a b a
= × × = × ×
= × − = −
4 2
2 4 4
12
12
2 2 2 2
( )base height base height
Area of a casing stone = (0.86 m)(0.86 m) = 0.7396 m2
Number of stones = ≈86 8120 7396
117 000.
Question 8 (e)
Question 8 (f) (i)
Question 8 (f) (ii)
LC HigHer LeveL SoLutionS SampLe paper 1 (© Educate.ie)
188.7 m 230 m 188.7 m
230 m
221 m
115 m
221 m
115 m
x
115 221
221 115 188 7
2 2 2
2 2
+ =
= − =
x
x . m
Length of square =+
=2 188 7 230
5012 15( . ) . m
Question 8 (d)
Sample 1
Paper 2
26 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Im
Re
1
2
3
4
0 1 2 3 4
w
z
30o
60o
z i
z
z
= +
= + = + = =
= = ⇒ = = =
∴ =
−
2 2 3
2 2 3 4 12 16 4
2 32
3 3 603
2 2
1
( )
tan tan ( )θ θπo
443 3
cos sinπ π+
i
w i
w
w
= +
= + = + = =
= ⇒ =
= =
∴ =
−
3
3 1 3 1 4 2
13
13
306
2
2 2
1
( ) ( )
tan tanθ θπo
ccos sinπ π6 6+
i
zw i i
i
= +
+
= +
43 3
26 6
82 2
cos sin cos sin
cos sin
π π π π
π π
= +=
8 08( )ii
‘According to De Moivre’s theorem, when two complex numbers are multiplied together, the arguments are added and the moduli are multiplied to form the new complex number.’
zw
i
ii=
+
+
= +
43 3
26 6
26 6
cos sin
cos sincos sin
π π
π ππ π
= +
= +2 3
212
3i i
‘According to De Moivre’s theorem, when two complex numbers are divided, the arguments are subtracted and the moduli are divided to form the new complex number.’
zw
i
i
= +
= +
1414
14
14
26 6
2 146
146
cos sin
cos sin
π π
π π
= +
= +
= +2 7
373
2 12
32
2 1 314 14 13cos sin ( )π πi i i
z r z= =, arg θ
z r i= +(cos sin )θ θ
Question 2 (25 marks)Question 2 (a)
Question 2 (b) (i) Question 2 (b) (ii)
Question 2 (c) (i) Question 2 (c) (ii)
Question 2 (c) (iii)
(De Moivre’s Theorem)[ (cos sin )] (cos sin )r i r n i nn nq q q q+ = +
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
log ( ) log
log ( ) loglog
log ( ) log
9 3
99
9
99
12
2 0
23
0
2 0
x x
x x
x x
+ − =
+ − =
+ − =
llog ( ) log
log
(
9 9
9 2
20
2
2
2 2 02 0
2 9 1
22 0
2
x xxx
xx
x xx xx
+ − =+
=
+= =
+ =
− − =− ))( )x
x+ =
=1 0
2
Question 1 (25 marks)Question 1 (a)
sample paper 2: paper 1
log log loga a axy
x y
= −
a y y xxa= ⇔ =log
log loglogb
a
a
x xb
=
Question 1 (b) (i)
[x = −1 is not allowed as x > 0.]
53
5 4 33 2 1
10
52
5 42 1
10
=
× ×× ×
=
=
××
=
( )p q p q p q p q p q+ =
+
+
+
5 5 0 4 1 3 2 2 350
51
52
53
++
+
= + + + + +
54
55
5 10 10 5
1 4 0 5
5 4 1 3 2 2 3 1 4
p q p q
p p q p q p q p q q55
T p q33 2 3 210 10 0 6 0 4 0 3456= = =( . ) ( . ) .
Question 1 (b) (ii)
Question 1 (b) (iii)
Higher Level, Educate.ie Sample 2, Paper 1 27
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Im
Re
1
2
3
4
0 1 2 3 4
w
z
30o
60o
z i
z
z
= +
= + = + = =
= = ⇒ = = =
∴ =
−
2 2 3
2 2 3 4 12 16 4
2 32
3 3 603
2 2
1
( )
tan tan ( )θ θπo
443 3
cos sinπ π+
i
w i
w
w
= +
= + = + = =
= ⇒ =
= =
∴ =
−
3
3 1 3 1 4 2
13
13
306
2
2 2
1
( ) ( )
tan tanθ θπo
ccos sinπ π6 6+
i
zw i i
i
= +
+
= +
43 3
26 6
82 2
cos sin cos sin
cos sin
π π π π
π π
= +=
8 08( )ii
‘According to De Moivre’s theorem, when two complex numbers are multiplied together, the arguments are added and the moduli are multiplied to form the new complex number.’
zw
i
ii=
+
+
= +
43 3
26 6
26 6
cos sin
cos sincos sin
π π
π ππ π
= +
= +2 3
212
3i i
‘According to De Moivre’s theorem, when two complex numbers are divided, the arguments are subtracted and the moduli are divided to form the new complex number.’
zw
i
i
= +
= +
1414
14
14
26 6
2 146
146
cos sin
cos sin
π π
π π
= +
= +
= +2 7
373
2 12
32
2 1 314 14 13cos sin ( )π πi i i
z r z= =, arg θ
z r i= +(cos sin )θ θ
Question 2 (25 marks)Question 2 (a)
Question 2 (b) (i) Question 2 (b) (ii)
Question 2 (c) (i) Question 2 (c) (ii)
Question 2 (c) (iii)
(De Moivre’s Theorem)[ (cos sin )] (cos sin )r i r n i nn nq q q q+ = +
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
log ( ) log
log ( ) loglog
log ( ) log
9 3
99
9
99
12
2 0
23
0
2 0
x x
x x
x x
+ − =
+ − =
+ − =
llog ( ) log
log
(
9 9
9 2
20
2
2
2 2 02 0
2 9 1
22 0
2
x xxx
xx
x xx xx
+ − =+
=
+= =
+ =
− − =− ))( )x
x+ =
=1 0
2
Question 1 (25 marks)Question 1 (a)
sample paper 2: paper 1
log log loga a axy
x y
= −
a y y xxa= ⇔ =log
log loglogb
a
a
x xb
=
Question 1 (b) (i)
[x = −1 is not allowed as x > 0.]
53
5 4 33 2 1
10
52
5 42 1
10
=
× ×× ×
=
=
××
=
( )p q p q p q p q p q+ =
+
+
+
5 5 0 4 1 3 2 2 350
51
52
53
++
+
= + + + + +
54
55
5 10 10 5
1 4 0 5
5 4 1 3 2 2 3 1 4
p q p q
p p q p q p q p q q55
T p q33 2 3 210 10 0 6 0 4 0 3456= = =( . ) ( . ) .
Question 1 (b) (ii)
Question 1 (b) (iii)
Sample 2
Paper 1
28 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)Yes. Each value of y corresponds to only one value of x.
It is not injective because certain values of y correspond to two values of x.
Local maximum is at y = 2.
Question 5 (b)
Question 5 (c)
Question 5 (d)
Question 5 (e)
B
A
x
y
f x( ) = 2x
h x( )
g x x( ) = log2
x
y
f x( ) = 2x
y x=
g(x) is the inverse function of f (x).Reflect the curve for f (x) by an axial symmetry through the line y = x to get its inverse function.
f x yyy xy x
f x y g x
x
x
( )log loglog loglog
( ) log ( )
= =
===
∴ = =−
22
22 2
2 2
21
2
x yA
h x aa
h x x
= ⇒ = =∴
∈ ⇒ = − − +∴ =
= − −
0 2 10 1
0 1 1 122 1
0
2
2
( , )( , ) ( ) ( )
( ) ( )
h x xx
xxx
B
( ) ( )( )
( )
( ,
= − −
∴ = − −
− =− =
∴ =
2 12 2 1
1 01 0
11 2
2
2
2
Local Maximum ))( , ) ( )?( )
( )
B f xf x x
1 22
2 21
∈
=
= True
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
100, 90, 81,...... a = 100, r = 0.9Which term is equal to 50, half of its original mass?
50 100 0 90 5 0 9
0 5 1 0 9
1
1
10 10
10
=
== −
∴ =
−
−
( . ). .
log ( . ) ( ) log ( . )log
n
n
n
n (( . )log ( . )
.0 50 9
1 7 5810
+ = days
S
S
S S
n
nn
n
=−
= −
= =
− =
−
∞
∞
108 1 162 1
108 162
0 05
162 1
13
23
13
23
( ( ) ) ( ( ) )
.
( (( ) ) .
( ) .
log loglo
13
13
10 10
162 0 05
162 0 05
3 32403 3240
n
n
n
n
n
− =
=
==
∴ =gglog
.10
10
32403
7 36=
Question 3 (25 marks)Question 3 (a) Question 3 (b)
Seven days must elapse before it is less than half its original mass.
Eight terms must be added together so that the sum differs from the sum to infinity by less than 0.05.
Question 4 (25 marks)
2
1
3
4
y
�1�2�3�4�5
�1
5
x
54321
y = 4
( 3, 4)�
(5, 4)
(1, 0)
(0, 1)
( 1)�0,
y x y xy xy x
= − ⇒ = ± −
= − → −= − + →
1 11 0 1 1 0
1
( ): ( , ), ( , )Intercepts
Interceptts: ( , ), ( , )0 1 1 0
Question 4 (a)Draw each of the straight line graphs by plotting their intercepts.
Question 4 (b)
Point of intersection: (1, 0)
Points of intersection: (−3, 4), (5, 4)Question 4 (c)x < –3, x > 5
Higher Level, Educate.ie Sample 2, Paper 1 29
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)Yes. Each value of y corresponds to only one value of x.
It is not injective because certain values of y correspond to two values of x.
Local maximum is at y = 2.
Question 5 (b)
Question 5 (c)
Question 5 (d)
Question 5 (e)
B
A
x
y
f x( ) = 2x
h x( )
g x x( ) = log2
x
y
f x( ) = 2x
y x=
g(x) is the inverse function of f (x).Reflect the curve for f (x) by an axial symmetry through the line y = x to get its inverse function.
f x yyy xy x
f x y g x
x
x
( )log loglog loglog
( ) log ( )
= =
===
∴ = =−
22
22 2
2 2
21
2
x yA
h x aa
h x x
= ⇒ = =∴
∈ ⇒ = − − +∴ =
= − −
0 2 10 1
0 1 1 122 1
0
2
2
( , )( , ) ( ) ( )
( ) ( )
h x xx
xxx
B
( ) ( )( )
( )
( ,
= − −
∴ = − −
− =− =
∴ =
2 12 2 1
1 01 0
11 2
2
2
2
Local Maximum ))( , ) ( )?( )
( )
B f xf x x
1 22
2 21
∈
=
= True
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
100, 90, 81,...... a = 100, r = 0.9Which term is equal to 50, half of its original mass?
50 100 0 90 5 0 9
0 5 1 0 9
1
1
10 10
10
=
== −
∴ =
−
−
( . ). .
log ( . ) ( ) log ( . )log
n
n
n
n (( . )log ( . )
.0 50 9
1 7 5810
+ = days
S
S
S S
n
nn
n
=−
= −
= =
− =
−
∞
∞
108 1 162 1
108 162
0 05
162 1
13
23
13
23
( ( ) ) ( ( ) )
.
( (( ) ) .
( ) .
log loglo
13
13
10 10
162 0 05
162 0 05
3 32403 3240
n
n
n
n
n
− =
=
==
∴ =gglog
.10
10
32403
7 36=
Question 3 (25 marks)Question 3 (a) Question 3 (b)
Seven days must elapse before it is less than half its original mass.
Eight terms must be added together so that the sum differs from the sum to infinity by less than 0.05.
Question 4 (25 marks)
2
1
3
4
y
�1�2�3�4�5
�1
5
x
54321
y = 4
( 3, 4)�
(5, 4)
(1, 0)
(0, 1)
( 1)�0,
y x y xy xy x
= − ⇒ = ± −
= − → −= − + →
1 11 0 1 1 0
1
( ): ( , ), ( , )Intercepts
Interceptts: ( , ), ( , )0 1 1 0
Question 4 (a)Draw each of the straight line graphs by plotting their intercepts.
Question 4 (b)
Point of intersection: (1, 0)
Points of intersection: (−3, 4), (5, 4)Question 4 (c)x < –3, x > 5
Sample 2
Paper 1
30 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
V x x xdVdx
x x
dVdx
x x
= − +
= − +
= ⇒ − + =
4 130 1000
12 260 1000
0 12 260 1000
3 2
2
2 00
3 65 250 03 50 5 0
5
2
503
x xx xx
− + =− − ==
( )( ), cm
VMax. ( ) ( ) ( )= − + = − + =4 5 130 5 1000 5 500 3250 5000 22503 2 3cm
l = 40 − 2(5) = 30 cm, b = 25 − 2(5) = 15 cm, h = 5 cm
Maximum Volume: dVdx
= 0
[Ignore the second solution as it will cause one of the sides to be negative.]
Question 7 (d)
dVdt
t
V t dt t t c
V t cV t
= − +
= − + = − − +
= = =
∴ = −
∫
( )
( )
:
2 5
2 5 5
2250 0 2250
2
when22 5 2250− +t
− − + =
+ − =− + =
∴ =
t tt tt tt
2
2
5 2250 05 2250 045 50 0
45( )( )
s
V rdVdt
r drdt
drdt r
A rdAdt
r drdt
rr
=
= × = ⇒ =
=
= × = ×
13
3
22
2
3 3
2 2 3
π
ππ
π
π ππ 22
2
6
62
3
=
= =
=
rdAdt r
cm /s2
Question 7 (e)
h
r
45o
Area A
Question 7 (f) (i)
Question 7 (f) (ii)
tan 45 1
13
2 13
3
o = ⇒ =
∴ =
= =
rh
rh
r hV r h rπ π
V x x xx x xx x xx
= − +
− + =
− + − =
=
4 130 10004 130 1000 15122 65 500 756 0
1
3 2
3 2
3
:: ( ) ( ) ( ): ( ) ( ) ( )2 1 65 1 500 1 756 319 0
2 2 2 65 2 500 2 756
3
3
− + − = − ≠
= − + − =x 00
Question 7 (c)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
f x g xx x xx xx x
xgg
( ) ( )
( )( ),
( )(
=
− = +
= − += − −
∴ == + =
5 30 4 30 1 3
1 31 1 3 43
2
2
))( , ), ( , )
= + =3 3 61 4 3 6A B
Question 6 (b) Question 6 (c)
A f x g x dx
x x dx
x x x
= −
= − + −
= − + −
= −
∫
∫
( ( ) ( ))
( )
[ ]
{ (
1
3
2
1
3
13
3 213
13
4 3
2 3
3)) ( ) ( )} { ( ) ( ) ( )}3 2 13
3 2
13
43
2 3 3 3 1 2 1 3 19 18 9 2 3
+ − − − + −
= − + − + − +
=
C D
f x dx
x x dx
( , ), ( , )
( )
( )
0 0 5 01
5 0
5
0
5
15
2
0
5
15
Average value =−
= −
=
∫
∫[[ ]
{ ( ) ( ) } { }( )
52
2 13
305
15
52
2 13
3
15
1252
1253
256
5 5 0
x x−
= − −
= − =
V x x xx x x xx x x
= − −
= − − +
= − +
=
( )( )( )( )
40 2 25 21000 80 50 41000 130 4
100
2
2
00 130 42 3x x x− +
S x x x x x xx x x x
= − + − + − −
= − + − + −
2 40 2 2 25 2 40 2 25 280 4 50 4 10002 2
( ) ( ) ( )( )880 50 4
1000 4
2
2
x x xx
− +
= −
600 1000 44 400
10010
2
2
2
= −
=
=∴ =
xx
xx cm
(40 2 ) cm� x
(25 2 ) cm� x
x x
x
x
x x
x
x
Question 7 (50 marks)Question 7 (a) (i)
l = 40 – 2x, b = 25 – 2x, h = x
Question 7 (a) (ii)
Question 7 (b) (i) Question 7 (b) (ii)
A
x
y
DC
f x( )B
g x( )
Higher Level, Educate.ie Sample 2, Paper 1 31
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
V x x xdVdx
x x
dVdx
x x
= − +
= − +
= ⇒ − + =
4 130 1000
12 260 1000
0 12 260 1000
3 2
2
2 00
3 65 250 03 50 5 0
5
2
503
x xx xx
− + =− − ==
( )( ), cm
VMax. ( ) ( ) ( )= − + = − + =4 5 130 5 1000 5 500 3250 5000 22503 2 3cm
l = 40 − 2(5) = 30 cm, b = 25 − 2(5) = 15 cm, h = 5 cm
Maximum Volume: dVdx
= 0
[Ignore the second solution as it will cause one of the sides to be negative.]
Question 7 (d)
dVdt
t
V t dt t t c
V t cV t
= − +
= − + = − − +
= = =
∴ = −
∫
( )
( )
:
2 5
2 5 5
2250 0 2250
2
when22 5 2250− +t
− − + =
+ − =− + =
∴ =
t tt tt tt
2
2
5 2250 05 2250 045 50 0
45( )( )
s
V rdVdt
r drdt
drdt r
A rdAdt
r drdt
rr
=
= × = ⇒ =
=
= × = ×
13
3
22
2
3 3
2 2 3
π
ππ
π
π ππ 22
2
6
62
3
=
= =
=
rdAdt r
cm /s2
Question 7 (e)
h
r
45o
Area A
Question 7 (f) (i)
Question 7 (f) (ii)
tan 45 1
13
2 13
3
o = ⇒ =
∴ =
= =
rh
rh
r hV r h rπ π
V x x xx x xx x xx
= − +
− + =
− + − =
=
4 130 10004 130 1000 15122 65 500 756 0
1
3 2
3 2
3
:: ( ) ( ) ( ): ( ) ( ) ( )2 1 65 1 500 1 756 319 0
2 2 2 65 2 500 2 756
3
3
− + − = − ≠
= − + − =x 00
Question 7 (c)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
f x g xx x xx xx x
xgg
( ) ( )
( )( ),
( )(
=
− = +
= − += − −
∴ == + =
5 30 4 30 1 3
1 31 1 3 43
2
2
))( , ), ( , )
= + =3 3 61 4 3 6A B
Question 6 (b) Question 6 (c)
A f x g x dx
x x dx
x x x
= −
= − + −
= − + −
= −
∫
∫
( ( ) ( ))
( )
[ ]
{ (
1
3
2
1
3
13
3 213
13
4 3
2 3
3)) ( ) ( )} { ( ) ( ) ( )}3 2 13
3 2
13
43
2 3 3 3 1 2 1 3 19 18 9 2 3
+ − − − + −
= − + − + − +
=
C D
f x dx
x x dx
( , ), ( , )
( )
( )
0 0 5 01
5 0
5
0
5
15
2
0
5
15
Average value =−
= −
=
∫
∫[[ ]
{ ( ) ( ) } { }( )
52
2 13
305
15
52
2 13
3
15
1252
1253
256
5 5 0
x x−
= − −
= − =
V x x xx x x xx x x
= − −
= − − +
= − +
=
( )( )( )( )
40 2 25 21000 80 50 41000 130 4
100
2
2
00 130 42 3x x x− +
S x x x x x xx x x x
= − + − + − −
= − + − + −
2 40 2 2 25 2 40 2 25 280 4 50 4 10002 2
( ) ( ) ( )( )880 50 4
1000 4
2
2
x x xx
− +
= −
600 1000 44 400
10010
2
2
2
= −
=
=∴ =
xx
xx cm
(40 2 ) cm� x
(25 2 ) cm� x
x x
x
x
x x
x
x
Question 7 (50 marks)Question 7 (a) (i)
l = 40 – 2x, b = 25 – 2x, h = x
Question 7 (a) (ii)
Question 7 (b) (i) Question 7 (b) (ii)
A
x
y
DC
f x( )B
g x( )
Sample 2
Paper 1
32 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 9 (50 marks)
Question 9 (a)A
s
B
: ..
: ..
.
s ut tt
s t tt tt
= fi =\ =
= += +
\ +
100 9 110 99
5 0 56100 5 0 56
0 56
2
2
2 55 100 0
5 25 2242 0 56
9 62
t
t
- =
= - ± +¥
=.
. s
91 5 0 560 56 4 1 0
0 56 4 1 04 1
0 567 32
2
2
. .
. .( . . )
..
.
t t tt t
t t
t
= +- =- =
= = s
s t= = =9 1 9 1 7 32 66 6. . ( . ) . m
P l r= +2 2p
400 2 2200
200
= += +
= -
l rl r
r l
pp
p
A rl l l l l= = - = -2 2 200 400 2 2( )p p p
dAdl
l
dAdl
l
l
l
= -
= fi - =
=
\ =
400 4
0 400 4 0
400 4
100
p p
p p
p pm
r
r r
r
l
l
D
A B
C
Question 9 (b)
Question 9 (c)
Question 9 (d)
Question 9 (e) (i)
Question 9 (e) (ii)B wins the race.
Question 9 (e) (iii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 8 (50 marks)
M ss
=
= =log log10 10 1 0
M As
M As
M M As
1 101
2 101
2 1 101
8 3
4
4
=
=
=
− =
log .
log
log −
− = ×
− =∴
log
. log
. log
101
2 101
1
2 10
8 3 4
8 3 4
As
M As
sA
MMM 2 10 4 8 3 8 9= + =log . .
Question 8 (a)
Question 8 (b)
M As
M As
M M As
1 101
2 102
1 2 101
8 3
4
=
=
=
=
− =
log .
log
log −
= ×
=
∴
log
. log log
102
101
210
1
2
4 3
As
As
sA
AA
A11
2
4 310 19953A
= =.
Question 8 (c)
M A A
M As
As
M A A
M
1 1
1 101 1 5 9
2 2
2
5 9
5 9 10
6 5
= =
=
= ⇒ =
= =
=
. ,
log .
. ,
lo
.
gg . .10
2 2 6 56 5 10As
As
A
= ⇒ =
=Fractionalchange in amplitude 22 1
1
2
16 5
5 90 6
1
1010
1 10 1 2 98
298
−= −
=××
− = − =
=
AA
AA
ss
.
.. .
% %change
Modified Mercalli Scale
II
I
IV
III
VI
V
VIII
VII
X
IX
XII
XI
4.5
8
2.5
3.5
7.5
5.5
6.5
1.5
2
3
4
5
6
7
Felt by few persons at rest, especially on
upper floors; delicately suspended objects
may swing.
Detected only by sensitive instruments
Felt noticeably indoors, but not always recognised
as earthquake; standing autos rock slightly,
vibration like passing truck.
Felt indoors by many, outdoors by few, at night
some may awaken; dishes, windows, doors
disturbed; autos rock noticeably
Felt by most people; some breakage of dishes,
windows, and plaster; disturbance of tall objects
Felt by all, many frightened and run outdoors;
falling plaster and chimneys; sand and mud
ejected; drivers of autos disturbed
Everybody runs outdoors; damage to buildings
varies depending on quality of construction;
noticed by drivers of autos
Panel walls thrown out of frames; fall of walls,
monuments, chimneys; sand and mud ejected;
drivers of autos disturbed
Buildings shifted off foundations, cracked, thrown
out of plumb; ground cracked; underground pipes
broken
Most masonry and frame structures destroyed;
ground cracked, rails bent, landslides
Few structures remain standing; bridges destroyed,
fissures in ground, pipes broken, landslides,
rails bent
Damage total; waves seen on ground surface,
lines of sight and level distorted, objects thrown
up in air
Richter
Magnitude
Scale
Question 8 (d)
6 510
1010
10 10 10 316
10 4
6 54
6 5 4 2 5
. log
.
. .
=
=
∴ = × = =
−
−
−
A
A
A cm
E = × = ×+ ×1 74 10 2 7 105 1 44 4 3 11. .( . . ) J
Question 8 (e)
Question 8 (f)
Higher Level, Educate.ie Sample 2, Paper 1 33
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 9 (50 marks)
Question 9 (a)A
s
B
: ..
: ..
.
s ut tt
s t tt tt
= fi =\ =
= += +
\ +
100 9 110 99
5 0 56100 5 0 56
0 56
2
2
2 55 100 0
5 25 2242 0 56
9 62
t
t
- =
= - ± +¥
=.
. s
91 5 0 560 56 4 1 0
0 56 4 1 04 1
0 567 32
2
2
. .
. .( . . )
..
.
t t tt t
t t
t
= +- =- =
= = s
s t= = =9 1 9 1 7 32 66 6. . ( . ) . m
P l r= +2 2p
400 2 2200
200
= += +
= -
l rl r
r l
pp
p
A rl l l l l= = - = -2 2 200 400 2 2( )p p p
dAdl
l
dAdl
l
l
l
= -
= fi - =
=
\ =
400 4
0 400 4 0
400 4
100
p p
p p
p pm
r
r r
r
l
l
D
A B
C
Question 9 (b)
Question 9 (c)
Question 9 (d)
Question 9 (e) (i)
Question 9 (e) (ii)B wins the race.
Question 9 (e) (iii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 8 (50 marks)
M ss
=
= =log log10 10 1 0
M As
M As
M M As
1 101
2 101
2 1 101
8 3
4
4
=
=
=
− =
log .
log
log −
− = ×
− =∴
log
. log
. log
101
2 101
1
2 10
8 3 4
8 3 4
As
M As
sA
MMM 2 10 4 8 3 8 9= + =log . .
Question 8 (a)
Question 8 (b)
M As
M As
M M As
1 101
2 102
1 2 101
8 3
4
=
=
=
=
− =
log .
log
log −
= ×
=
∴
log
. log log
102
101
210
1
2
4 3
As
As
sA
AA
A11
2
4 310 19953A
= =.
Question 8 (c)
M A A
M As
As
M A A
M
1 1
1 101 1 5 9
2 2
2
5 9
5 9 10
6 5
= =
=
= ⇒ =
= =
=
. ,
log .
. ,
lo
.
gg . .10
2 2 6 56 5 10As
As
A
= ⇒ =
=Fractionalchange in amplitude 22 1
1
2
16 5
5 90 6
1
1010
1 10 1 2 98
298
−= −
=××
− = − =
=
AA
AA
ss
.
.. .
% %change
Modified Mercalli Scale
II
I
IV
III
VI
V
VIII
VII
X
IX
XII
XI
4.5
8
2.5
3.5
7.5
5.5
6.5
1.5
2
3
4
5
6
7
Felt by few persons at rest, especially on
upper floors; delicately suspended objects
may swing.
Detected only by sensitive instruments
Felt noticeably indoors, but not always recognised
as earthquake; standing autos rock slightly,
vibration like passing truck.
Felt indoors by many, outdoors by few, at night
some may awaken; dishes, windows, doors
disturbed; autos rock noticeably
Felt by most people; some breakage of dishes,
windows, and plaster; disturbance of tall objects
Felt by all, many frightened and run outdoors;
falling plaster and chimneys; sand and mud
ejected; drivers of autos disturbed
Everybody runs outdoors; damage to buildings
varies depending on quality of construction;
noticed by drivers of autos
Panel walls thrown out of frames; fall of walls,
monuments, chimneys; sand and mud ejected;
drivers of autos disturbed
Buildings shifted off foundations, cracked, thrown
out of plumb; ground cracked; underground pipes
broken
Most masonry and frame structures destroyed;
ground cracked, rails bent, landslides
Few structures remain standing; bridges destroyed,
fissures in ground, pipes broken, landslides,
rails bent
Damage total; waves seen on ground surface,
lines of sight and level distorted, objects thrown
up in air
Richter
Magnitude
Scale
Question 8 (d)
6 510
1010
10 10 10 316
10 4
6 54
6 5 4 2 5
. log
.
. .
=
=
∴ = × = =
−
−
−
A
A
A cm
E = × = ×+ ×1 74 10 2 7 105 1 44 4 3 11. .( . . ) J
Question 8 (e)
Question 8 (f)
Sample 2
Paper 1
34 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
The perpendicular line from O bisects the chord.The distance from the centre to the chord is 3.
l mx y kQ l m k k ml mx y m
:( , ) :
:
− + =− − ∈ − + + = ⇒ = −− + − =
01 3 3 0 3
3 0
The chord passing through Q is called l.
dax by c
a bd x yl mx y m
m m
=+ +
+= =
− + − =
=− + −
1 1
2 2
1 13 3 03 0
33 0
, ( , ) ( , ):
( ) ( ) 33
1
3 1 3 3
3 1 4 3
9 9 16 24 97 24 0
7
2
2
2
2 2
2
m
m m m
m m
m m mm mm m
+
+ = + −
+ = −
+ = − +
− =−( 224 0
0 247
),
==m
Q( 1, 3)� �
4l
r = 5r = 53
8
4 Slope m
O(3, 0)
s
[The perpendicular distance of the chord l from the centre O is 3.]
Slope of t: m = − 43
Circle s: Centre O(3, 0), r = 5
Equation of OQ: Point O(3, 0), m = 34
my xy xx y
=
− = −
= −− − =
34
340 3
4 3 93 4 9 0
( )
Find the point of intersection of lines t and OQ.
4 3 13 0 33 4 9 0 4
12 9 39 012 16 36 0
25 75
x yx y
x yx y
y
+ + = ×− − = ×−
+ + =− + + =
+
( )( )
== ⇒ = −
= − + − + = ⇒ = −∴ = −
0 3
3 4 3 3 13 0 4 41
y
y x xx
: ( )
Point of contact Q(−1, −3)
Question 2 (25 marks)
O(3, 0)
t
r = 5 Q
s
4 3 13 0 33 4 9 0 4
12 9 39 012 16 36 0
25 75
x yx y
x yx y
y
+ + = ×− − = ×−
+ + =− + + =
+
( )( )
== ⇒ = −
= − + − + = ⇒ = −∴ = −
0 3
3 4 3 3 13 0 4 41
y
y x xx
: ( )
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
The diagonal bisects the area of a parallelogram. Find the area of triangle ABD and multiply the answer by 2.
ABD
( , ) ( , )( , ) ( , )( , ) ( , )
1 3 0 04 4 3 1
1 7 2 4
→→
− → −
Area of parallelogram ABCD = 14
A(6, 0)O(0, 0)
B(0, 8)
y
x
Intercepts of 2x + 3y = c: D c E c( , ), ( , )12
130 0
O D c E c
ODE c c c
( , ), ( , ), ( , )
( )( ) ( )( )
0 0 0 0
0 0
12
13
12
12
13
12
16Area ∆ = − = 22
12
12
0 0 6 0 0 80 0 6 8 48
O A BOAB
OD
( , ), ( , ), ( , )( )( ) ( )( )Area
Area
∆ = − =
∆ EE OAB
c
c
c
c
= ∆
∴ = ×
=
=
∴ = ± = ±
12
12
16
2 12
12
16
2
2
48
24
144
144 12
Area
Question 1 (25 marks)Question 1 (a)
sample paper 2: paper 2
A x y x y= −
= − −
= +
=
12 1 2 2 1
12
12
3 4 2 1
12 27
( ) ( )( )
Question 1 (b)
B(4, 4)
A(1, 3)
C(2, 8)
D( 1, 7)�
note: The diagram in the question is a rough sketch showing the relative positions of the points. A grid is drawn whenever we wish to display the absolute positions of the points.
35Higher Level, Educate.ie Sample 2, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
The perpendicular line from O bisects the chord.The distance from the centre to the chord is 3.
l mx y kQ l m k k ml mx y m
:( , ) :
:
− + =− − ∈ − + + = ⇒ = −− + − =
01 3 3 0 3
3 0
The chord passing through Q is called l.
dax by c
a bd x yl mx y m
m m
=+ +
+= =
− + − =
=− + −
1 1
2 2
1 13 3 03 0
33 0
, ( , ) ( , ):
( ) ( ) 33
1
3 1 3 3
3 1 4 3
9 9 16 24 97 24 0
7
2
2
2
2 2
2
m
m m m
m m
m m mm mm m
+
+ = + −
+ = −
+ = − +
− =−( 224 0
0 247
),
==m
Q( 1, 3)� �
4l
r = 5r = 53
8
4 Slope m
O(3, 0)
s
[The perpendicular distance of the chord l from the centre O is 3.]
Slope of t: m = − 43
Circle s: Centre O(3, 0), r = 5
Equation of OQ: Point O(3, 0), m = 34
my xy xx y
=
− = −
= −− − =
34
340 3
4 3 93 4 9 0
( )
Find the point of intersection of lines t and OQ.
4 3 13 0 33 4 9 0 4
12 9 39 012 16 36 0
25 75
x yx y
x yx y
y
+ + = ×− − = ×−
+ + =− + + =
+
( )( )
== ⇒ = −
= − + − + = ⇒ = −∴ = −
0 3
3 4 3 3 13 0 4 41
y
y x xx
: ( )
Point of contact Q(−1, −3)
Question 2 (25 marks)
O(3, 0)
t
r = 5 Q
s
4 3 13 0 33 4 9 0 4
12 9 39 012 16 36 0
25 75
x yx y
x yx y
y
+ + = ×− − = ×−
+ + =− + + =
+
( )( )
== ⇒ = −
= − + − + = ⇒ = −∴ = −
0 3
3 4 3 3 13 0 4 41
y
y x xx
: ( )
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
The diagonal bisects the area of a parallelogram. Find the area of triangle ABD and multiply the answer by 2.
ABD
( , ) ( , )( , ) ( , )( , ) ( , )
1 3 0 04 4 3 1
1 7 2 4
→→
− → −
Area of parallelogram ABCD = 14
A(6, 0)O(0, 0)
B(0, 8)
y
x
Intercepts of 2x + 3y = c: D c E c( , ), ( , )12
130 0
O D c E c
ODE c c c
( , ), ( , ), ( , )
( )( ) ( )( )
0 0 0 0
0 0
12
13
12
12
13
12
16Area ∆ = − = 22
12
12
0 0 6 0 0 80 0 6 8 48
O A BOAB
OD
( , ), ( , ), ( , )( )( ) ( )( )Area
Area
∆ = − =
∆ EE OAB
c
c
c
c
= ∆
∴ = ×
=
=
∴ = ± = ±
12
12
16
2 12
12
16
2
2
48
24
144
144 12
Area
Question 1 (25 marks)Question 1 (a)
sample paper 2: paper 2
A x y x y= −
= − −
= +
=
12 1 2 2 1
12
12
3 4 2 1
12 27
( ) ( )( )
Question 1 (b)
B(4, 4)
A(1, 3)
C(2, 8)
D( 1, 7)�
note: The diagram in the question is a rough sketch showing the relative positions of the points. A grid is drawn whenever we wish to display the absolute positions of the points.
Sample 2
Paper 2
36 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
30–35 2 < 35 2
35–40 3 < 40 5
40–45 9 < 45 14
45–50 12 < 50 26
50–55 22 < 55 48
55–60 (LQ) 46 < 60 94
60–65 (M) 58 < 65 152
65–70 50 < 70 202
70–75 (UQ) 40 < 75 242
75–80 32 < 80 274
80–85 16 < 85 290
290
Life expectancy (years)
Number of countries
Cumulative number of countries
Life expectancy (years)
Number of countries = 290Median class: 290(0.5) + 0.5 = 145.5 (Class 60−65)Upper quartile class: 290(0.75) + 0.75 = 218.25 (Class 70−75)Lower quartile class: 290(0.25) + 0.25 = 72.75 (Class 55−60)
Question 5 (a)Question 5 (25 marks)
Question 5 (b)
Nu
mb
er
of
Co
un
trie
sLife Expectancy (years)
5030 6055
[3]
4540 65 7570 8580
40
30
20
10
60
50
Median = 145.5M
35
[2]
[9][12]
[22]
[46]
[58]
(152)(94)
Modal class: 60−65Shape: Skewed left
Question 5 (c) Question 5 (d)
M = +−
=60 145 5 94
585 64 4. .
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 3 (a)
Question 3 (25 marks)
α
Ladder
3 m
10 m
30o
h
x
d
y
sin sin3010
10 30 5o o m= ⇒ = =h h
tantan
.
30 5 530
5 3
5 3 3 5 66
oo m
m
= ⇒ = =
= − =x
x
d
tan.
tan.
.α α= ⇒ =
=
−55 66
55 66
41 461 o
Question 3 (b)
Question 3 (c)
sin
sin .
sin ..
α =
=
= =
5
41 46 5
541 46
7 55
y
y
y
o
o m
Length of ladder protruding beyond the top of the wall = 10 − 7.55 = 2.45 m
Question 3 (d)
Condition: There are only two possible outcomes (success or failure) in each trial.Condition: There is a fixed number of trials n.Condition: The probability of success p is fixed from trial to trial.Condition: The trials are independent.Condition: The binomial random variable is the number of successes in n trials.
P P
P x C
( ) , ( )
( ) ( ) (
Income Income< = > =
≥ =
€ €32000 32000
8
12
12
108
12
2 12 )) ( ) ( ) ( ) ( ) .8 10
912
1 12
9 1010
12
0 12
10 0 055+ + =C C
Question 4 (a)Question 4 (25 marks)
Question 4 (b) (i)
P x P C C( ) ( ) ( ) ( ) ( ) ( ) .≥ = − = − − =2 1 1 1 0 99100
12
10 12
0 101
12
9 12
1None or
Question 4 (b) (ii)
37Higher Level, Educate.ie Sample 2, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
30–35 2 < 35 2
35–40 3 < 40 5
40–45 9 < 45 14
45–50 12 < 50 26
50–55 22 < 55 48
55–60 (LQ) 46 < 60 94
60–65 (M) 58 < 65 152
65–70 50 < 70 202
70–75 (UQ) 40 < 75 242
75–80 32 < 80 274
80–85 16 < 85 290
290
Life expectancy (years)
Number of countries
Cumulative number of countries
Life expectancy (years)
Number of countries = 290Median class: 290(0.5) + 0.5 = 145.5 (Class 60−65)Upper quartile class: 290(0.75) + 0.75 = 218.25 (Class 70−75)Lower quartile class: 290(0.25) + 0.25 = 72.75 (Class 55−60)
Question 5 (a)Question 5 (25 marks)
Question 5 (b)
Nu
mb
er
of
Co
un
trie
s
Life Expectancy (years)
5030 6055
[3]
4540 65 7570 8580
40
30
20
10
60
50
Median = 145.5M
35
[2]
[9][12]
[22]
[46]
[58]
(152)(94)
Modal class: 60−65Shape: Skewed left
Question 5 (c) Question 5 (d)
M = +−
=60 145 5 94
585 64 4. .
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 3 (a)
Question 3 (25 marks)
α
Ladder
3 m
10 m
30o
h
x
d
y
sin sin3010
10 30 5o o m= ⇒ = =h h
tantan
.
30 5 530
5 3
5 3 3 5 66
oo m
m
= ⇒ = =
= − =x
x
d
tan.
tan.
.α α= ⇒ =
=
−55 66
55 66
41 461 o
Question 3 (b)
Question 3 (c)
sin
sin .
sin ..
α =
=
= =
5
41 46 5
541 46
7 55
y
y
y
o
o m
Length of ladder protruding beyond the top of the wall = 10 − 7.55 = 2.45 m
Question 3 (d)
Condition: There are only two possible outcomes (success or failure) in each trial.Condition: There is a fixed number of trials n.Condition: The probability of success p is fixed from trial to trial.Condition: The trials are independent.Condition: The binomial random variable is the number of successes in n trials.
P P
P x C
( ) , ( )
( ) ( ) (
Income Income< = > =
≥ =
€ €32000 32000
8
12
12
108
12
2 12 )) ( ) ( ) ( ) ( ) .8 10
912
1 12
9 1010
12
0 12
10 0 055+ + =C C
Question 4 (a)Question 4 (25 marks)
Question 4 (b) (i)
P x P C C( ) ( ) ( ) ( ) ( ) ( ) .≥ = − = − − =2 1 1 1 0 99100
12
10 12
0 101
12
9 12
1None or
Question 4 (b) (ii)
Sample 2
Paper 2
38 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 7 (75 marks)
R I
R II
I
=
= = =
=
∴ =×
100
10 1 159
10 1 100159
159 10
GDPGDP billion. %, , ?
.
.
€
11100
16 1= € . billion
GDP per capita = =€
€159000000000
458825234654
7
12 13 14 15 16 1711
3
4
5
6
11
8
9
10
Unem
plo
ym
ent
Rate
Investment to GDP ratio
Run = 16 14�
Question 7 (a) (i) Question 7 (a) (ii)
Question 7 (b)
The data shows that the most effective way to reduce the unemployment rate is to increase investment to GDP ratio.
A. Linear, B. Negative shape, C. Very strong correlation
Question 7 (c) (i)
Question 7 (c) (ii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
7 cm
Question 6 (a)
Question 6 (25 marks)
Draw a line of length 7 cm with your ruler.Open your compass to a radius of 7 cm using this line. Placing the point of the compass on each end point of the line draw arcs of radius 7 cm.Draw lines from the end points of the line to the point of intersection of the two arcs.An equilateral triangle of side 7 cm has been constructed.
BE BE
AD
2 2 2
2 2 2
10 16 2 10 16 60 196 14
6 16 2 6 16
= + − = ⇒ =
= + −
( )( ) cos
( )( ) co
o
ss 60 196 14o = ⇒ =
∴⇒ =
AD
BE AD
E
B
6
6
60o
10 10
60o
CA
D
6
10
60o
CA
D
6
10
120o
E
B
6
10
C
120o
Triangles ACD and BCE are congruent (SAS).
Question 6 (b)
Question 6 (c)
39Higher Level, Educate.ie Sample 2, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Question 7 (75 marks)
R I
R II
I
=
= = =
=
∴ =×
100
10 1 159
10 1 100159
159 10
GDPGDP billion. %, , ?
.
.
€
11100
16 1= € . billion
GDP per capita = =€
€159000000000
458825234654
7
12 13 14 15 16 1711
3
4
5
6
11
8
9
10
Unem
plo
ym
ent
Rate
Investment to GDP ratio
Run = 16 14�
Question 7 (a) (i) Question 7 (a) (ii)
Question 7 (b)
The data shows that the most effective way to reduce the unemployment rate is to increase investment to GDP ratio.
A. Linear, B. Negative shape, C. Very strong correlation
Question 7 (c) (i)
Question 7 (c) (ii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
7 cm
Question 6 (a)
Question 6 (25 marks)
Draw a line of length 7 cm with your ruler.Open your compass to a radius of 7 cm using this line. Placing the point of the compass on each end point of the line draw arcs of radius 7 cm.Draw lines from the end points of the line to the point of intersection of the two arcs.An equilateral triangle of side 7 cm has been constructed.
BE BE
AD
2 2 2
2 2 2
10 16 2 10 16 60 196 14
6 16 2 6 16
= + − = ⇒ =
= + −
( )( ) cos
( )( ) co
o
ss 60 196 14o = ⇒ =
∴⇒ =
AD
BE AD
E
B
6
6
60o
10 10
60o
CA
D
6
10
60o
CA
D
6
10
120o
E
B
6
10
C
120o
Triangles ACD and BCE are congruent (SAS).
Question 6 (b)
Question 6 (c)
Sample 2
Paper 2
40 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
O
B
P
A
C
r =1 16 cm
r = 9 cm2
r
Q
D
7 cm 9 cm
16 cm
r1 = 16 cmr2 = 9 cm
|PQ| = |PC| + |CQ| = r1 + r2 = 16 cm + 9 cm = 25 cm
725
x
x
x
2 2 2
2 2
7 25
25 7 24
+ =
= − = cm
tan( )
tan
. .
∠ =
∴ ∠ =
= =
−
APQ
APQ
247
247
73 74 1 287
1
o rads
A r= = =12
2 12
2 216 1 287 164 7θ ( ) ( . ) . cm
Question 8 (75 marks)
Question 8 (a) (i) Question 8 (a) (ii)
Question 8 (b) (i) Question 8 (b) (ii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
CaSio CaLCuLator (fx-85GT PLUS)Steps to find r:Press Mode.Press 2: StatPress 2: A + BxInput your x and y valuesPress AC ButtonPress Shift followed by the Number 1Press 5: RegPress 3: rPress =
r = –0.9767
( , . ), ( , . ). . .
14 8 4 16 6 38 4 6 314 16
1 1m =−−
= −
m x yy xy x
= − =− = − −− = − +
1 1 14 8 48 4 1 1 14
8 4 1 1 15 41
1 2. , ( , ) ( , . )( . ) . ( )
. . ... .1 23 8 0x y+ − =
y xx= + − =
∴ =3 1 1 3 23 8 0
18 9: . ( ) .
.
7
12 13 14 15 16 1711
3
4
5
6
11
8
9
10
Unem
plo
ym
ent
Rate
From 1948 to Present
Investment to GDP ratio
Question 7 (d) Question 7 (e) (i)
Question 7 (e) (ii)
Question 7 (e) (iii)
The 11 year plot is misleading as the 64 year plot shows little correlation between the unemployment rate and investment to GDP ratio. It is a prime example of someone using statistics to support their own position.
Question 7 (f) (i)
Question 7 (f) (ii)Yes
41Higher Level, Educate.ie Sample 2, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
O
B
P
A
C
r =1 16 cm
r = 9 cm2
r
Q
D
7 cm 9 cm
16 cm
r1 = 16 cmr2 = 9 cm
|PQ| = |PC| + |CQ| = r1 + r2 = 16 cm + 9 cm = 25 cm
725
x
x
x
2 2 2
2 2
7 25
25 7 24
+ =
= − = cm
tan( )
tan
. .
∠ =
∴ ∠ =
= =
−
APQ
APQ
247
247
73 74 1 287
1
o rads
A r= = =12
2 12
2 216 1 287 164 7θ ( ) ( . ) . cm
Question 8 (75 marks)
Question 8 (a) (i) Question 8 (a) (ii)
Question 8 (b) (i) Question 8 (b) (ii)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
CaSio CaLCuLator (fx-85GT PLUS)Steps to find r:Press Mode.Press 2: StatPress 2: A + BxInput your x and y valuesPress AC ButtonPress Shift followed by the Number 1Press 5: RegPress 3: rPress =
r = –0.9767
( , . ), ( , . ). . .
14 8 4 16 6 38 4 6 314 16
1 1m =−−
= −
m x yy xy x
= − =− = − −− = − +
1 1 14 8 48 4 1 1 14
8 4 1 1 15 41
1 2. , ( , ) ( , . )( . ) . ( )
. . ... .1 23 8 0x y+ − =
y xx= + − =
∴ =3 1 1 3 23 8 0
18 9: . ( ) .
.
7
12 13 14 15 16 1711
3
4
5
6
11
8
9
10
Unem
plo
ym
ent
Rate
From 1948 to Present
Investment to GDP ratio
Question 7 (d) Question 7 (e) (i)
Question 7 (e) (ii)
Question 7 (e) (iii)
The 11 year plot is misleading as the 64 year plot shows little correlation between the unemployment rate and investment to GDP ratio. It is a prime example of someone using statistics to support their own position.
Question 7 (f) (i)
Question 7 (f) (ii)Yes
Sample 2
Paper 2
42 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Area of space between wheels = Area of trapezium − Area of sector APC − Area of sector CQB − Area of smallest wheel
Area of sector CQB:
O
B
P
A
C
r =1 16 cm
r = 9 cm2
r
Q
D
�
α = − =
∠ = + = =
=
90 73 74 16 2616 26 90 106 26 1 855
12
2
o o o
o o o rads. .. . .CQB
A r θθ = =12
2 29 1 855 75 13( ) ( . ) . cm
Area of space between wheels = − − −
≈300 164 7 75 13 144
4933
22. . π cm
% of air space to area of three wheels =+ +
× ≈33
16 9 14449
100 32 2
2
π
% %
Question 8 (f)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
O
B
y
A
C
(16 - r) (9 + r)
r
Q
D
(16 + r)
(9 - r)
P
z
y r ry r ry r r r
2 2 2
2 2 2
2
16 1616 1616 16 16 16
+ − = +
= + − −
= + + − + −
( ) ( )( ) ( )( )( ++
= =
=
ry r r
y r
)( )( )2 32 2 64
8
z r rz r rz r r r rz
2 2 2
2 2 2
2
2
9 99 99 9 9 91
+ − = +
= + − −
= + + − + − +
=
( ) ( )( ) ( )( )( )( 88 2 36
6
)( )r r
z r
=
=
y z
r r
r
r
r
+ =
+ =
=
= =
∴ =
24
8 6 24
14 242414
127
14449
Area of trapezium ABQP: A = + = =12
216 9 24 25 12 300( )( ) ( ) cm
Question 8 (c) (i) Question 8 (c) (ii)
Question 8 (d)
Question 8 (e)
43Higher Level, Educate.ie Sample 2, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
Area of space between wheels = Area of trapezium − Area of sector APC − Area of sector CQB − Area of smallest wheel
Area of sector CQB:
O
B
P
A
C
r =1 16 cm
r = 9 cm2
r
Q
D
�
α = − =
∠ = + = =
=
90 73 74 16 2616 26 90 106 26 1 855
12
2
o o o
o o o rads. .. . .CQB
A r θθ = =12
2 29 1 855 75 13( ) ( . ) . cm
Area of space between wheels = − − −
≈300 164 7 75 13 144
4933
22. . π cm
% of air space to area of three wheels =+ +
× ≈33
16 9 14449
100 32 2
2
π
% %
Question 8 (f)
LC HigHer LeveL SoLutionS SampLe paper 2 (© Educate.ie)
O
B
y
A
C
(16 - r) (9 + r)
r
Q
D
(16 + r)
(9 - r)
P
z
y r ry r ry r r r
2 2 2
2 2 2
2
16 1616 1616 16 16 16
+ − = +
= + − −
= + + − + −
( ) ( )( ) ( )( )( ++
= =
=
ry r r
y r
)( )( )2 32 2 64
8
z r rz r rz r r r rz
2 2 2
2 2 2
2
2
9 99 99 9 9 91
+ − = +
= + − −
= + + − + − +
=
( ) ( )( ) ( )( )( )( 88 2 36
6
)( )r r
z r
=
=
y z
r r
r
r
r
+ =
+ =
=
= =
∴ =
24
8 6 24
14 242414
127
14449
Area of trapezium ABQP: A = + = =12
216 9 24 25 12 300( )( ) ( ) cm
Question 8 (c) (i) Question 8 (c) (ii)
Question 8 (d)
Question 8 (e)
Sample 2
Paper 2
44 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 2 (25 marks)Question 2 (a)
log ( ) loglog ( ) log
log
4 4
4 4
4 2
6 1 2 26 1 2 26 1 2
6
x xx xxx
x
+ − =+ − =
+
=
++=
+ =
− − =+ − =
=
1 4
6 1 1616 6 1 08 1 2 1 0
22
2
2
12
xx xx xx x
x( )( )
log log loga a axy
x y
= −
a y y xxa= ⇔ =log
F ab
F a F b
F a bF F a F a
= −
⇒ == − =
( ) ( )
( )( ) ( ) ( )11 0
F y F y F y Fy
F y F F yF y
y
( ) ( )
( ) [ ( ) ( )]( )
21
1
10
=
= −
= − −= − + FF yF y
( )( )= 2
Fx
F F x
F xF x
1 1
0
= −
= −= −
( ) ( )
( )( )
Question 2 (b) (i) Question 2 (b) (ii) Question 2 (b) (iii)
[ x = − 18 is not allowed as log ( )4
18− is not defined.]
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
x x xxxx x
3 2
3 2
3
3 2 02 2 3 2 2 2 023
+ + − =
= − − + − − − =∴ +
∴ +
: ( ) ( )( ) is a factor
22 2
3 2
3
2 2 12 2 1 2
3 2 13
+ − = + + −
= + + + − −∴ = + ⇒ =
∴ +
x x x kxx k x k x
k kx x
( )( )( ) ( )
22 22 2 1 0+ − = + + − =x x x x( )( )
Question 1 (25 marks)Question 1 (a)
sample paper 3: paper 1
Rationalise the denominators by multiplying above and below by the conjugate of the denominator.
Question 1 (b)
x x
x
x
2
2
1 0
1 1 4 1 12 1
1 1 42
1 52
2 1 52
+ − =
=− ± − −
=− ± +
=− ±
∴ = −− ±
( )( )( )
,
[Line up the coefficients.]
[Solve the quadratic equation.]
11 2
1 21 2
1 21 2
2 1
11 2
1 21 2
1 21 2
2 1
( )( )( )
( )( )( )
+×
−−
=−−
= −
−×
++
=+−
= − −
1 1 2
1 1 2
1 2 1
11 2
11 2
2
−
=
− = ±
± =
=+ −
x
x
x
x ,
45Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 2 (25 marks)Question 2 (a)
log ( ) loglog ( ) log
log
4 4
4 4
4 2
6 1 2 26 1 2 26 1 2
6
x xx xxx
x
+ − =+ − =
+
=
++=
+ =
− − =+ − =
=
1 4
6 1 1616 6 1 08 1 2 1 0
22
2
2
12
xx xx xx x
x( )( )
log log loga a axy
x y
= −
a y y xxa= ⇔ =log
F ab
F a F b
F a bF F a F a
= −
⇒ == − =
( ) ( )
( )( ) ( ) ( )11 0
F y F y F y Fy
F y F F yF y
y
( ) ( )
( ) [ ( ) ( )]( )
21
1
10
=
= −
= − −= − + FF yF y
( )( )= 2
Fx
F F x
F xF x
1 1
0
= −
= −= −
( ) ( )
( )( )
Question 2 (b) (i) Question 2 (b) (ii) Question 2 (b) (iii)
[ x = − 18 is not allowed as log ( )4
18− is not defined.]
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
x x xxxx x
3 2
3 2
3
3 2 02 2 3 2 2 2 023
+ + − =
= − − + − − − =∴ +
∴ +
: ( ) ( )( ) is a factor
22 2
3 2
3
2 2 12 2 1 2
3 2 13
+ − = + + −
= + + + − −∴ = + ⇒ =
∴ +
x x x kxx k x k x
k kx x
( )( )( ) ( )
22 22 2 1 0+ − = + + − =x x x x( )( )
Question 1 (25 marks)Question 1 (a)
sample paper 3: paper 1
Rationalise the denominators by multiplying above and below by the conjugate of the denominator.
Question 1 (b)
x x
x
x
2
2
1 0
1 1 4 1 12 1
1 1 42
1 52
2 1 52
+ − =
=− ± − −
=− ± +
=− ±
∴ = −− ±
( )( )( )
,
[Line up the coefficients.]
[Solve the quadratic equation.]
11 2
1 21 2
1 21 2
2 1
11 2
1 21 2
1 21 2
2 1
( )( )( )
( )( )( )
+×
−−
=−−
= −
−×
++
=+−
= − −
1 1 2
1 1 2
1 2 1
11 2
11 2
2
−
=
− = ±
± =
=+ −
x
x
x
x , Sample 3
Paper 1
46 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
S = {6, 12, 18, 24,.....}S3 = {12, 24, 36, 48,...}Yes, all elements of S3 are elements of S.
Question 4 (b) (i)
S = {6, 12, 18, 24,.....}S1 = {3, 6, 9, 12,...}No. 9 is an element of S1 but not an element of S.
S = {6, 12, 18, 24,.....}S2 = {9, 18, 27, 36,...}No. 9 is an element of S2 but not an element of S.
Question 4 (b) (ii)
Question 4 (b) (iii)
Question 4 (c)
z r z= =, arg θ
z r i= +(cos sin )θ θ
Z
N
Q
A
70
−8
− 56
23
Question 4 (25 marks)Question 4 (a) (i) & (ii)
θ
z
n z i
n z
= =
+
= =
0 2 518
518
1 2 1718
1
2
: cos sin
: cos
p p
p
+
= =
+
i
n z i
sin
: cos sin
1718
2 2 2918
293
p
p pp18
z i
z
= − +
= − + = + = =
=−
= =
∴ = −
4 3 4
4 3 4 48 16 64 8
44 3
13
13
2 2
1
( )
tan tan ,
tan
θ α
α
= =
= − =
∴ = +
306
656
8 56
2
o
Second quadrant:
p
p p p
p p
θ
z ncos + +
=
+
+
+i n n i nsin cos sin56
2 8 5 126
5 12p p p p p p66
8 5 126
5 126
13
13
=+
+
+
z n i ncos sinp p p p
=
+
+
+
13
2 5 1218
5 1218
cos sinp p p pn i n
where α is the related angle in the first quadrant.
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Three consecutive numbers: n − 1, n, n + 1
S n n nn n n n nn
= − + + +
= − + + + + +
= +
( ) ( )1 12 1 2 1
3 2
2 2 2
2 2 2
2
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
3 23
22 2
3n n+
= +
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = 1: n = + + =1 7 3 1 8 181: ( ) [Therefore, true for n = 1.]
2. Assume true for n = k: Assume n k k a ak= + + = ∈: ,7 3 8 9 �
3. Prove true for n = k + 1: Prove 7 3 1 8 91k k b b+ + + + = ∈( ) , �
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
Proof:7 3 1 8
7 7 3 3 87 9 3 8 3 1163 21
1k
k
kk
a k ka k
+ + + +
= + + += − − + += − −
( )( )( )
556 3 1163 18 459 7 2 59
+ += − −= − −= ∈
ka ka k
b b[ ]
, �
47Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
S = {6, 12, 18, 24,.....}S3 = {12, 24, 36, 48,...}Yes, all elements of S3 are elements of S.
Question 4 (b) (i)
S = {6, 12, 18, 24,.....}S1 = {3, 6, 9, 12,...}No. 9 is an element of S1 but not an element of S.
S = {6, 12, 18, 24,.....}S2 = {9, 18, 27, 36,...}No. 9 is an element of S2 but not an element of S.
Question 4 (b) (ii)
Question 4 (b) (iii)
Question 4 (c)
z r z= =, arg θ
z r i= +(cos sin )θ θ
Z
N
Q
A
70
−8
− 56
23
Question 4 (25 marks)Question 4 (a) (i) & (ii)
θ
z
n z i
n z
= =
+
= =
0 2 518
518
1 2 1718
1
2
: cos sin
: cos
p p
p
+
= =
+
i
n z i
sin
: cos sin
1718
2 2 2918
293
p
p pp18
z i
z
= − +
= − + = + = =
=−
= =
∴ = −
4 3 4
4 3 4 48 16 64 8
44 3
13
13
2 2
1
( )
tan tan ,
tan
θ α
α
= =
= − =
∴ = +
306
656
8 56
2
o
Second quadrant:
p
p p p
p p
θ
z ncos + +
=
+
+
+i n n i nsin cos sin56
2 8 5 126
5 12p p p p p p66
8 5 126
5 126
13
13
=+
+
+
z n i ncos sinp p p p
=
+
+
+
13
2 5 1218
5 1218
cos sinp p p pn i n
where α is the related angle in the first quadrant.
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Three consecutive numbers: n − 1, n, n + 1
S n n nn n n n nn
= − + + +
= − + + + + +
= +
( ) ( )1 12 1 2 1
3 2
2 2 2
2 2 2
2
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
3 23
22 2
3n n+
= +
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = 1: n = + + =1 7 3 1 8 181: ( ) [Therefore, true for n = 1.]
2. Assume true for n = k: Assume n k k a ak= + + = ∈: ,7 3 8 9 �
3. Prove true for n = k + 1: Prove 7 3 1 8 91k k b b+ + + + = ∈( ) , �
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
Proof:7 3 1 8
7 7 3 3 87 9 3 8 3 1163 21
1k
k
kk
a k ka k
+ + + +
= + + += − − + += − −
( )( )( )
556 3 1163 18 459 7 2 59
+ += − −= − −= ∈
ka ka k
b b[ ]
, �
Sample 3
Paper 1
48 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
y
x
0.5
0.3
0.2
20
0.4
0.1
1510c = 1.4 5
y
x
0.5
0.3
0.2
20
0.4
0.1
15105e = 2.7
The maximum value of f (x) as calculated in part (b) is e.∴ ≈e 2 7.
Question 5 (e) (ii)
10 1010
10 1010
10
10c c cc
f x xx
f
f c cc
f f
= ⇒ =
=
=
=
∴ =
ln ln
( ) ln
( ) ln
( ) ln
( ) (cc c) .⇒ ≈1 4
Question 5 (e) (iii)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
x2
y
x
x1
x3
BA C
f x y xx
dydx
x xx
xx
dydx
xx
x
( ) ln
( ) (ln )( ) ln
ln
= =
=−
=−
= ⇒−
=
−
1
2 2
2
1 1
0 1 0
1 llnln
( ) ln
: ,
xx x e
f e ee e
ee
== ⇒ =
= =
01
1
1TP
dydx
xx
d ydx
x x xx
x x x xx
x
=−
=− − −
=− − +
=
1
1 2
2 2
2
2
2
2 1
2 2
4
ln
( ) ( ln )( )( )
ln
−− +
=
− +=− +
=−
= −=
3 2
3 2 3 2 1
4
2
2 4 4 4 3
x x xx
d ydx
e e ee
e ee
ee ex e
ln
ln<<
∴
0
1ee
, is a local maximum
a ba b
b a a baa
bb
b a
b a
=
==
∴ =
ln lnln lnln ln
It is not injective because there is more than one x value mapping on to the same y value.
It is surjective because every y value has a corresonding x value.
Question 5 (b) Question 5 (c)
Question 5 (d)
y
x
0.5
0.3
0.2
20
0.4
0.1
15102 54
0.35
Calculator: ln ln .22
44
0 3466= =
Question 5 (e) (i)
2 4 22
44
2 22
4 44
2 4 0 35
4 2= ⇒ =
=
=
=
∴ = =
ln ln
( ) ln
( ) ln
( ) ln
( ) ( ) .
f x xx
f
f
f f
49Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
y
x
0.5
0.3
0.2
20
0.4
0.1
1510c = 1.4 5
y
x
0.5
0.3
0.2
20
0.4
0.1
15105e = 2.7
The maximum value of f (x) as calculated in part (b) is e.∴ ≈e 2 7.
Question 5 (e) (ii)
10 1010
10 1010
10
10c c cc
f x xx
f
f c cc
f f
= ⇒ =
=
=
=
∴ =
ln ln
( ) ln
( ) ln
( ) ln
( ) (cc c) .⇒ ≈1 4
Question 5 (e) (iii)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
x2
y
x
x1
x3
BA C
f x y xx
dydx
x xx
xx
dydx
xx
x
( ) ln
( ) (ln )( ) ln
ln
= =
=−
=−
= ⇒−
=
−
1
2 2
2
1 1
0 1 0
1 llnln
( ) ln
: ,
xx x e
f e ee e
ee
== ⇒ =
= =
01
1
1TP
dydx
xx
d ydx
x x xx
x x x xx
x
=−
=− − −
=− − +
=
1
1 2
2 2
2
2
2
2 1
2 2
4
ln
( ) ( ln )( )( )
ln
−− +
=
− +=− +
=−
= −=
3 2
3 2 3 2 1
4
2
2 4 4 4 3
x x xx
d ydx
e e ee
e ee
ee ex e
ln
ln<<
∴
0
1ee
, is a local maximum
a ba b
b a a baa
bb
b a
b a
=
==
∴ =
ln lnln lnln ln
It is not injective because there is more than one x value mapping on to the same y value.
It is surjective because every y value has a corresonding x value.
Question 5 (b) Question 5 (c)
Question 5 (d)
y
x
0.5
0.3
0.2
20
0.4
0.1
15102 54
0.35
Calculator: ln ln .22
44
0 3466= =
Question 5 (e) (i)
2 4 22
44
2 22
4 44
2 4 0 35
4 2= ⇒ =
=
=
=
∴ = =
ln ln
( ) ln
( ) ln
( ) ln
( ) ( ) .
f x xx
f
f
f f
Sample 3
Paper 1
50 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Solve equations (1), (2) and (3) simultaneously.
′ = − −
⇒ ′ = ⇒ − − =
−
f x x xD f x x xx
( )( )
6 4 100 6 4 10 0
3
2
2
2
is a turning point22 5 0
3 5 1 01 5
353
xx xx
x D
− =− + =
∴ = −
=
( )( ),
-coordinate of
B C g x
m
g x x y
( , ) ( , ) ( )
( ):
3 0 0 60 63 0
2
2
and
Slope
Equation of
− ∈
=+−
=
− ++ =∈ − + = ⇒ = −
− − =
kB g x k kx y
g x g x
03 0 6 0 0 6
2 6 0( , ) ( ) :
( ): ( )Equation of == = −y x2 6
A g x f x dx
x x x x dx
x x x
= −
= − − + + +
= − + +
∫
∫
( ( ) ( ))
( )
(
0
3
3 2
0
3
3 2
2 6 2 2 10 6
2 2 12 ))
{
0
3
4 3 2
0
3
12
4 23
3 2
0
3
12
24
23
122
6
∫
= − + +
= − + +
= −
dx
x x x
x x x
(( ) ( ) ( ) }3 3 6 3 04 23
3 2
632
+ + −
=
Question 6 (b) Question 6 (c)
Question 6 (d)
− + − =+ + =− + =
+ +
a b ca b ca b c
a
69 3 23 2 0
8 4
.....( )...( )...( )
( ) ( ) :
123
1 2 bb a ba b
aa
= ⇒ + =+ − =
∴ = +∴ =
8 2 22 6
4 82
...( )( ) ( ) : .....( )
...( ) ( )
41 3 5
4 5
SSubstitute into equation Substitute into
( ) : ( )4 2 2 2 2+ = ⇒ = −b b equation ( ) :
( )1 − − − = ⇒ = −
∴ = − − −
2 2 6 102 2 10 63 2
c cf x x x x
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
A( 1, 0)�
B(3, 0)
C(0, 6)�
y
D
y g x= ( )
y f x= ( )
x
f x ax bx cx dA f x f a b c d
( )( , ) ( ) : ( ) ( ) ( ) ( )
= + + +
− ∈ − = − + − + − + =
3 2
3 21 0 1 1 1 1 000
3 0 3 3 3 3 02
3 2
∴− + − + =
∈ = + + + =∴
a b c d
B f x f a b c d
...( )
( , ) ( ) : ( ) ( ) ( ) ( )
1
77 9 3 0
0 6 0 0 0 0 63 2
a b c d
C f x f a b c d
+ + + =
− ∈ = + + + = −
...( )
( , ) ( ) : ( ) ( ) ( ) ( )
2
∴∴ = −
∴− + − =∴ + + = ⇒ + + =
d
a b ca b c a b c
6
627 9 3 6 9 3 2
...( )...( )
12
f x ax bx cx df x ax bx cA
( )( )( , )
= + + +
′ = + +
−
3 2
23 21 0 is a turning point ⇒⇒ ′ − = − + − + =
∴ − + =f a b c
a b c( ) ( ) ( )
...( )1 3 1 2 1 0
3 2 0
2
3
51Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Solve equations (1), (2) and (3) simultaneously.
′ = − −
⇒ ′ = ⇒ − − =
−
f x x xD f x x xx
( )( )
6 4 100 6 4 10 0
3
2
2
2
is a turning point22 5 0
3 5 1 01 5
353
xx xx
x D
− =− + =
∴ = −
=
( )( ),
-coordinate of
B C g x
m
g x x y
( , ) ( , ) ( )
( ):
3 0 0 60 63 0
2
2
and
Slope
Equation of
− ∈
=+−
=
− ++ =∈ − + = ⇒ = −
− − =
kB g x k kx y
g x g x
03 0 6 0 0 6
2 6 0( , ) ( ) :
( ): ( )Equation of == = −y x2 6
A g x f x dx
x x x x dx
x x x
= −
= − − + + +
= − + +
∫
∫
( ( ) ( ))
( )
(
0
3
3 2
0
3
3 2
2 6 2 2 10 6
2 2 12 ))
{
0
3
4 3 2
0
3
12
4 23
3 2
0
3
12
24
23
122
6
∫
= − + +
= − + +
= −
dx
x x x
x x x
(( ) ( ) ( ) }3 3 6 3 04 23
3 2
632
+ + −
=
Question 6 (b) Question 6 (c)
Question 6 (d)
− + − =+ + =− + =
+ +
a b ca b ca b c
a
69 3 23 2 0
8 4
.....( )...( )...( )
( ) ( ) :
123
1 2 bb a ba b
aa
= ⇒ + =+ − =
∴ = +∴ =
8 2 22 6
4 82
...( )( ) ( ) : .....( )
...( ) ( )
41 3 5
4 5
SSubstitute into equation Substitute into
( ) : ( )4 2 2 2 2+ = ⇒ = −b b equation ( ) :
( )1 − − − = ⇒ = −
∴ = − − −
2 2 6 102 2 10 63 2
c cf x x x x
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
A( 1, 0)�
B(3, 0)
C(0, 6)�
y
D
y g x= ( )
y f x= ( )
x
f x ax bx cx dA f x f a b c d
( )( , ) ( ) : ( ) ( ) ( ) ( )
= + + +
− ∈ − = − + − + − + =
3 2
3 21 0 1 1 1 1 000
3 0 3 3 3 3 02
3 2
∴− + − + =
∈ = + + + =∴
a b c d
B f x f a b c d
...( )
( , ) ( ) : ( ) ( ) ( ) ( )
1
77 9 3 0
0 6 0 0 0 0 63 2
a b c d
C f x f a b c d
+ + + =
− ∈ = + + + = −
...( )
( , ) ( ) : ( ) ( ) ( ) ( )
2
∴∴ = −
∴− + − =∴ + + = ⇒ + + =
d
a b ca b c a b c
6
627 9 3 6 9 3 2
...( )...( )
12
f x ax bx cx df x ax bx cA
( )( )( , )
= + + +
′ = + +
−
3 2
23 21 0 is a turning point ⇒⇒ ′ − = − + − + =
∴ − + =f a b c
a b c( ) ( ) ( )
...( )1 3 1 2 1 0
3 2 0
2
3
Sample 3
Paper 1
52 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Let x = Mass of Sterling silverLet y = Mass of Britannia silverMass of ring = 28 g
x yx y
+ = ×+ =28 0 925
0 925 0 958 26 3224( . )
. . .
1 31 10347681
31 10347681
4031 1034768
40
40 1 286
T g
T g
T g
g T
=
=
=
∴ =
.
.
.
.
S C T pC
T
pS
= × ×=
= =
== × × =
0 9428
31 10347680 9
260 94 0 9 26 22
.
..
$. . $
Question 8 (b)
Question 8 (c) Question 8 (d)
10.00
15.00
0.00
5.00
30.00
35.00
20.00
25.00
45.00
50.00
40.00
US
D p
ertr
oy o
un
ce
Jul1
0
Jan11
Jul0
9
Jan10
Jul0
8
Jan09
Jul0
7
Jan08
Jan12
Jul1
2
Jul1
1
10.00
15.00
0.00
5.00
30.00
35.00
20.00
25.00
45.00
50.00
40.00
5 Year Pure SilverHigh 48.48 Low 8.92
0 925 0 925 25 90 925 0 958 26 3224
0 033 0 4224 12
. . .
. . .. . .
x yx y
y y
+ =+ =
= ⇒ = 88
28 12 8 15 2
g
g∴ = − =x . .
Question 8 (e)
Pure silver: 14 gMass of coin = 15 g
Purity = =1415
93 3gg
. %
Question 8 (50 marks)
Question 8 (a)
Pure silver is, of course, 100% pure silver.Britannia silver contains 95.8% pure silver.Sterling silver contains 92.5% pure silver.
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P Fr n=
+
1
100
P =( )
=500001 03
418746.
P =( )
=200
1 061337.
million
Question 7 (50 marks)Question 7 (a) Question 7 (b)
The exploration company should sell in 2020 because you would need 133 million now to make this money. However, the multinational company is only offering you 120 million now.
Question 7 (c) (i)P =
( )=
2001 08
116 77.. million
The exploration company should take the offer now because you would need 116.7 million now to make this money. However, the multinational company is offering you 120 million now.
Question 7 (c) (ii)
Year Reduction in Billions
1 3 2 3 3 3 4 3 5 3 6 2 7 2 8 2 9 2 10 2
120 2001
1 200120
53
1 53
53
1
7
7
17
17
=+
+ = =
+ =
∴ =
−
( )
( )
i
i
i
i == =0 076 7 6. . %
P = =3
1 062 83
.. billion
Question 7 (c) (iii) Question 7 (d) (i)
Question 7 (d) (ii)
P = + + + + + + + +3
1 063
1 063
1 063
1 063
1 062
1 062
1 062
1 062
2 3 4 5 6 7 8. . . . . . . . 11 062
1 063
1 061 1
1 061
1 061
1 061
1 062
1
9 10
2 3 4
. .
. . . . . .
+
= + + + +
+
0061 1
1 061
1 061
1 061
1 063
1 062
1 061
6 2 3 4
6
+ + + +
= +
. . . .
. .++ + + +
11 06
11 06
11 06
11 062 3 4. . . .
= +
−
−
3
1 062
1 06
1 1 11 06
1 11 06
6
5
. ..
.
= 18 9. billion
53Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Let x = Mass of Sterling silverLet y = Mass of Britannia silverMass of ring = 28 g
x yx y
+ = ×+ =28 0 925
0 925 0 958 26 3224( . )
. . .
1 31 10347681
31 10347681
4031 1034768
40
40 1 286
T g
T g
T g
g T
=
=
=
∴ =
.
.
.
.
S C T pC
T
pS
= × ×=
= =
== × × =
0 9428
31 10347680 9
260 94 0 9 26 22
.
..
$. . $
Question 8 (b)
Question 8 (c) Question 8 (d)
10.00
15.00
0.00
5.00
30.00
35.00
20.00
25.00
45.00
50.00
40.00
US
D p
ertr
oy o
un
ce
Jul1
0
Jan11
Jul0
9
Jan10
Jul0
8
Jan09
Jul0
7
Jan08
Jan12
Jul1
2
Jul1
1
10.00
15.00
0.00
5.00
30.00
35.00
20.00
25.00
45.00
50.00
40.00
5 Year Pure SilverHigh 48.48 Low 8.92
0 925 0 925 25 90 925 0 958 26 3224
0 033 0 4224 12
. . .
. . .. . .
x yx y
y y
+ =+ =
= ⇒ = 88
28 12 8 15 2
g
g∴ = − =x . .
Question 8 (e)
Pure silver: 14 gMass of coin = 15 g
Purity = =1415
93 3gg
. %
Question 8 (50 marks)
Question 8 (a)
Pure silver is, of course, 100% pure silver.Britannia silver contains 95.8% pure silver.Sterling silver contains 92.5% pure silver.
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P Fr n=
+
1
100
P =( )
=500001 03
418746.
P =( )
=200
1 061337.
million
Question 7 (50 marks)Question 7 (a) Question 7 (b)
The exploration company should sell in 2020 because you would need 133 million now to make this money. However, the multinational company is only offering you 120 million now.
Question 7 (c) (i)P =
( )=
2001 08
116 77.. million
The exploration company should take the offer now because you would need 116.7 million now to make this money. However, the multinational company is offering you 120 million now.
Question 7 (c) (ii)
Year Reduction in Billions
1 3 2 3 3 3 4 3 5 3 6 2 7 2 8 2 9 2 10 2
120 2001
1 200120
53
1 53
53
1
7
7
17
17
=+
+ = =
+ =
∴ =
−
( )
( )
i
i
i
i == =0 076 7 6. . %
P = =3
1 062 83
.. billion
Question 7 (c) (iii) Question 7 (d) (i)
Question 7 (d) (ii)
P = + + + + + + + +3
1 063
1 063
1 063
1 063
1 062
1 062
1 062
1 062
2 3 4 5 6 7 8. . . . . . . . 11 062
1 063
1 061 1
1 061
1 061
1 061
1 062
1
9 10
2 3 4
. .
. . . . . .
+
= + + + +
+
0061 1
1 061
1 061
1 061
1 063
1 062
1 061
6 2 3 4
6
+ + + +
= +
. . . .
. .++ + + +
11 06
11 06
11 06
11 062 3 4. . . .
= +
−
−
3
1 062
1 06
1 1 11 06
1 11 06
6
5
. ..
.
= 18 9. billion
Sample 3
Paper 1
54 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 9 (50 marks)
V r h hr
= = ⇒ =16 1622p p
A r rh
r rr
rr
= +
= +
= +
2 2
2 2 16
2 32
2
22
2
p p
p p
p p
A r rdAdr
r r
rr
r
r
= +
= ⇒ − =
− = ⇒ =
∴ =
−
−
2 32
0 4 32 0
4 32 0 8
2
2 1
2
23
p p
p p
p p
mm
A rr
A
= +
= + = + =
2 32
2 2 322
8 16 24
2
2 2
p p
p p p p pMin. mm( )
dmdt
e
dm e dt
m e ct m e c c
t
t
t
= −
= −
= +
= = = + ⇒
−
−
−
∫ ∫
110
110
11010
0 10 10 10 0, : ==
∴ = −
0
101
10m e t mg
t m e e= = = =− −5 10 10 6 0651
10 5 0 5: .( ) . mg
m e e= + =− −10 10 14 5361
106
10 . mg
2 10 10
0 2 10 2
10
110
110
110
12
110
5
1
= +
= +
=+
=
− − +
− −
−
e e
e e
e
T T
T
T
e
( )
. ( ). .112449
0 1244910 0 12449 20 835
110− =
∴ = − =
TT
ln( . )ln( . ) . hours
Question 9 (a) (i)
r (mm)
h (mm)
Question 9 (a) (ii)
Question 9 (b) (ii)
Question 9 (a) (iii) Question 9 (a) (iv)
Question 9 (b) (i)
Question 9 (b) (iii)
Question 9 (b) (iv)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
S C T pC
T
pS
= × ×=
= =
== × × =
0 9660
31 10347681 93
12 500 96 1 93 12 5
.
..
$ .. . . $223 16.
S C T pCTpS
= × ×==== × × =
0 961 93
27 500 96 1 93 27 5 50 95
..
$ .. . . $ .
Question 8 (e) (i) Question 8 (e) (ii)
Minimum value = $8.92Maximum value = $48.48
% change =−
× =( . . )
.% . %48 48 8 92
8 92100 443 5
Question 8 (f)
You thought you were not getting the full market value for pure silver. The scrap dealer was right.
S C T pCTpS
C
C
= × ×===== × ×
∴ = =
?
$$
. %
13025
25 1 302530
83 33
9025
3 6 3 6 31 1034768 111 97
0 83 83 3
= = × =
= =
. . . .
. . %
T g
93.2111.97
Question 8 (g)
55Higher Level, Educate.ie Sample 3, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 9 (50 marks)
V r h hr
= = ⇒ =16 1622p p
A r rh
r rr
rr
= +
= +
= +
2 2
2 2 16
2 32
2
22
2
p p
p p
p p
A r rdAdr
r r
rr
r
r
= +
= ⇒ − =
− = ⇒ =
∴ =
−
−
2 32
0 4 32 0
4 32 0 8
2
2 1
2
23
p p
p p
p p
mm
A rr
A
= +
= + = + =
2 32
2 2 322
8 16 24
2
2 2
p p
p p p p pMin. mm( )
dmdt
e
dm e dt
m e ct m e c c
t
t
t
= −
= −
= +
= = = + ⇒
−
−
−
∫ ∫
110
110
11010
0 10 10 10 0, : ==
∴ = −
0
101
10m e t mg
t m e e= = = =− −5 10 10 6 0651
10 5 0 5: .( ) . mg
m e e= + =− −10 10 14 5361
106
10 . mg
2 10 10
0 2 10 2
10
110
110
110
12
110
5
1
= +
= +
=+
=
− − +
− −
−
e e
e e
e
T T
T
T
e
( )
. ( ). .112449
0 1244910 0 12449 20 835
110− =
∴ = − =
TT
ln( . )ln( . ) . hours
Question 9 (a) (i)
r (mm)
h (mm)
Question 9 (a) (ii)
Question 9 (b) (ii)
Question 9 (a) (iii) Question 9 (a) (iv)
Question 9 (b) (i)
Question 9 (b) (iii)
Question 9 (b) (iv)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
S C T pC
T
pS
= × ×=
= =
== × × =
0 9660
31 10347681 93
12 500 96 1 93 12 5
.
..
$ .. . . $223 16.
S C T pCTpS
= × ×==== × × =
0 961 93
27 500 96 1 93 27 5 50 95
..
$ .. . . $ .
Question 8 (e) (i) Question 8 (e) (ii)
Minimum value = $8.92Maximum value = $48.48
% change =−
× =( . . )
.% . %48 48 8 92
8 92100 443 5
Question 8 (f)
You thought you were not getting the full market value for pure silver. The scrap dealer was right.
S C T pCTpS
C
C
= × ×===== × ×
∴ = =
?
$$
. %
13025
25 1 302530
83 33
9025
3 6 3 6 31 1034768 111 97
0 83 83 3
= = × =
= =
. . . .
. . %
T g
93.2111.97
Question 8 (g)
Sample 3
Paper 1
56 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Q
O(2, 0)
10c
P a b( , )Oc y xP a b c b a
PO
a b
a b
( , ):( , )
( ) ( )
( )
2 03
3
10
2 0 10
2
2
2
2 2
2 2
=
∈ ⇒ =
=
∴ − + − =
− + ==
− + =
− + + − =
− − =+ − =
∴ = −
102 3 104 4 3 10 0
6 02 3 0
2 3
2
2
2
( )
( )( )
,
a aa a aa aa a
abb bP Q
2 3 3 9 33 3 3 3= = ⇒ = ±
−( )
( , ), ( , )
A
C
B
F
E
D
G H
A x y B x y Ca b
( , ) ( , ), ( , ) ( , ), ?: :
( ) (
− = − = ==
∴− +
1 2 5 41 2
2 1 1 5
1 1 2 2
Ratio:))
( ) ( )
( , )
2 12 53
1
2 2 1 42 1
4 43
0
1 0
+=− +
=
∴+ −+
=−
=
∴C
D is the midpoint of BC:
B C
D
( , ), ( , )
, ( , )
5 4 1 05 1
24 02
3 2
−
=+ − +
= −
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
Question 2 (c)
Draw a line AC.On line AC mark out three arcs of equal radius with a compass.Draw the line FB.Using a set square and ruler draw lines EH and DG parallel to FB.The line AB has been divided into three equal parts.
C BA D
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
OC is divided in the ratio a:b = 1:2. bx axb a
by ayb a
1 2 1 2++
++
,O x y C x y A
a bx
( , ) ( , ), ( , ), ( , ): :
( )
2 3 6 61 2
2 2 12 1
1 1 2 2
2
− = −=
∴++
=
Ratio:
66 4 18 14
2 3 12 1
6 6 18 12
14 12
2 2
22 2
⇒ + = ⇒ =
∴− ++
= − ⇒ − + = − ⇒ = −
∴ −
x x
y y y
C
( )
( , ))
Equation of second circle: Centre C rx y
( , ),( ) ( )
14 12 1014 12 1002 2
− =
− + + =
s x y
O r
: ( ) ( )
( , ),
− + + =
− = =
2 3 25
2 3 25 5
2 2
Centre
10
5O(2, 3)�
B( 2, )��
A(6, )��
C x( , )2
y2
t
Slope of OA: m16 36 2
34
34
=− − −
−=−
= −( )
Slope of t: m243
=
Question 1 (25 marks)Question 1 (a)
sample paper 3: paper 2
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
A s( , ) ?( ) ( )
6 66 2 6 316 925
2 2
− ∈
− + − += +=
A O B( , ) ( , ) ( , )6 6 2 3 2 0− → − → −
Substitute A into s to see if it satisfies the equation of the circle.
Question 1 (b)
Question 1 (c)
Pass A through O by a central symmetry to find B.
Equation of t:
[Perpendicular slope]
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
Point dividing [PQ] in the ratio a:b
m x y A
y xy xt x y
= = −
+ = −
+ = −− − =
43 1 1
43
6 6
6 63 18 4 24
4 3 42 0
, ( ) ( , )
( )
:
,
57Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Q
O(2, 0)
10c
P a b( , )Oc y xP a b c b a
PO
a b
a b
( , ):( , )
( ) ( )
( )
2 03
3
10
2 0 10
2
2
2
2 2
2 2
=
∈ ⇒ =
=
∴ − + − =
− + ==
− + =
− + + − =
− − =+ − =
∴ = −
102 3 104 4 3 10 0
6 02 3 0
2 3
2
2
2
( )
( )( )
,
a aa a aa aa a
abb bP Q
2 3 3 9 33 3 3 3= = ⇒ = ±
−( )
( , ), ( , )
A
C
B
F
E
D
G H
A x y B x y Ca b
( , ) ( , ), ( , ) ( , ), ?: :
( ) (
− = − = ==
∴− +
1 2 5 41 2
2 1 1 5
1 1 2 2
Ratio:))
( ) ( )
( , )
2 12 53
1
2 2 1 42 1
4 43
0
1 0
+=− +
=
∴+ −+
=−
=
∴C
D is the midpoint of BC:
B C
D
( , ), ( , )
, ( , )
5 4 1 05 1
24 02
3 2
−
=+ − +
= −
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
Question 2 (c)
Draw a line AC.On line AC mark out three arcs of equal radius with a compass.Draw the line FB.Using a set square and ruler draw lines EH and DG parallel to FB.The line AB has been divided into three equal parts.
C BA D
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
OC is divided in the ratio a:b = 1:2. bx axb a
by ayb a
1 2 1 2++
++
,O x y C x y A
a bx
( , ) ( , ), ( , ), ( , ): :
( )
2 3 6 61 2
2 2 12 1
1 1 2 2
2
− = −=
∴++
=
Ratio:
66 4 18 14
2 3 12 1
6 6 18 12
14 12
2 2
22 2
⇒ + = ⇒ =
∴− ++
= − ⇒ − + = − ⇒ = −
∴ −
x x
y y y
C
( )
( , ))
Equation of second circle: Centre C rx y
( , ),( ) ( )
14 12 1014 12 1002 2
− =
− + + =
s x y
O r
: ( ) ( )
( , ),
− + + =
− = =
2 3 25
2 3 25 5
2 2
Centre
10
5O(2, 3)�
B( 2, )��
A(6, )��
C x( , )2
y2
t
Slope of OA: m16 36 2
34
34
=− − −
−=−
= −( )
Slope of t: m243
=
Question 1 (25 marks)Question 1 (a)
sample paper 3: paper 2
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
A s( , ) ?( ) ( )
6 66 2 6 316 925
2 2
− ∈
− + − += +=
A O B( , ) ( , ) ( , )6 6 2 3 2 0− → − → −
Substitute A into s to see if it satisfies the equation of the circle.
Question 1 (b)
Question 1 (c)
Pass A through O by a central symmetry to find B.
Equation of t:
[Perpendicular slope]
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
Point dividing [PQ] in the ratio a:b
m x y A
y xy xt x y
= = −
+ = −
+ = −− − =
43 1 1
43
6 6
6 63 18 4 24
4 3 42 0
, ( ) ( , )
( )
:
,
Sample 3
Paper 2
58 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Correlation 0.72 –0.90 0.96 –0.42Graph C B A D
Graph BGraph A Graph DGraph C
Graph A: Very tight clustering indicating r is close to 1 and a positive slope.Graph B: Mostly tight clustering indicating r is close enough to 1 and a negative slope.Graph C: Clustering is moderate indicating r is somewhere around 0.75 and a positive slope.Graph D: Weaker clustering indicating r is less than 0.5 and a negative slope.
Question 4 (25 marks)Question 4 (a)
1 2 3 4�4 �3 �2 �10
z1
z
�z1
Is P(z > z1) = P(z < –z1)? Yes
P(0) = 0
P(z > 0) = 0.5 P(z < 0) = 0.5
P z( )−∞ < < +∞ =1
P z( ) .≥ =0 0 5 P z( ) .≤ =0 0 5
Question 4 (b) (i) Question 4 (b) (ii)
Question 4 (b) (iii)
Question 4 (b) (iv)P z z P z z( ) ( )> = − ≤1 11
Question 4 (b) (v)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
r
8
h
12
4
8
h
12
4
r� �
124 4
34
12 3
=−
=−
∴ − =
hr
hrr h
V r h r rr r
r r
= = − =
− =
− + =
π π π2 2
2 3
3 2
12 3 2412 3 24
4 8 0
( ) f r r rffr
h rh
( )( )( )
= − += − + ≠= − + =
∴ == −
∴ = − =
3 24 81 1 4 8 02 8 16 8 0
212 3
12 6 6
Question 3 (25 marks)
The two highlighted triangles are similar triangles.
Question 3 (a) Question 3 (b) Question 3 (c)
59Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Correlation 0.72 –0.90 0.96 –0.42Graph C B A D
Graph BGraph A Graph DGraph C
Graph A: Very tight clustering indicating r is close to 1 and a positive slope.Graph B: Mostly tight clustering indicating r is close enough to 1 and a negative slope.Graph C: Clustering is moderate indicating r is somewhere around 0.75 and a positive slope.Graph D: Weaker clustering indicating r is less than 0.5 and a negative slope.
Question 4 (25 marks)Question 4 (a)
1 2 3 4�4 �3 �2 �10
z1
z
�z1
Is P(z > z1) = P(z < –z1)? Yes
P(0) = 0
P(z > 0) = 0.5 P(z < 0) = 0.5
P z( )−∞ < < +∞ =1
P z( ) .≥ =0 0 5 P z( ) .≤ =0 0 5
Question 4 (b) (i) Question 4 (b) (ii)
Question 4 (b) (iii)
Question 4 (b) (iv)P z z P z z( ) ( )> = − ≤1 11
Question 4 (b) (v)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
r
8
h
12
4
8
h
12
4
r� �
124 4
34
12 3
=−
=−
∴ − =
hr
hrr h
V r h r rr r
r r
= = − =
− =
− + =
π π π2 2
2 3
3 2
12 3 2412 3 24
4 8 0
( ) f r r rffr
h rh
( )( )( )
= − += − + ≠= − + =
∴ == −
∴ = − =
3 24 81 1 4 8 02 8 16 8 0
212 3
12 6 6
Question 3 (25 marks)
The two highlighted triangles are similar triangles.
Question 3 (a) Question 3 (b) Question 3 (c) Sample 3
Paper 2
60 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)Given: Three parallel lines AB, CD and EF such that C is on AE and D is on BF with |AC| = |CE|.
to prove: |BD| = |DF|.construction: Draw a line GH through D parallel to AE such that G is on AB and H is on EF.
proof: ACDG is a parallelogram ⇒ = =AC GD CE
CEHD is a parallelogram ⇒ =CE DH
∴ =GD DH
Now triangle GDB and triangle FDH are congruent (ASA) because:
∠ = ∠ =BGD FHD X [Alternate angles]
∠ = ∠ =GDB FDH Y [Vertically opposite angles]
GD DH= [Already proved]
∴ =BD DF
A
F
D
E
C
B
G
H
X
Y
Y
X
A
F
D
E
C
B
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
G: Germinate, NG: Not germinateP(G) = 0.6, P(NG) = 0.4
P(G, G, G, G) = = =( . )( . )( . )( . ) ( . )0 6 0 6 0 6 0 6 0 6 81625
4
P(G, NG, NG, NG) = × =( . )( . )( . )( . ) !!
0 6 0 4 0 4 0 4 43
96625
P(NG, NG, NG, NG) = = =( . )( . )( . )( . ) ( . )0 4 0 4 0 4 0 4 0 4 16625
4
Independence is necessary to do the calculation in (a) as the probability would change depending on whether or not the other seeds germinate. Independence may not be valid as the growing conditions (temperature, moisture and soil type) may vary from seed to seed.
Expected value = xP(x) = 4(0.6) = 2.4
Question 5 (25 marks)
Question 5 (a) (i)
Question 5 (a) (ii)
Question 5 (a) (iii)
Question 5 (b)
Question 5 (c)
Question 5 (d)Null hypothesis Ho: P = 0.9Alternative hypothesis H1: P < 0.9
Sample proportion = p = 97120
True population proportion = Sample proportion ± 1.96(Standard error of the proportion)
Standard error of the proportion = -p pn
( )1
True population proportion = ±-
=97120
1 961120
0 797
12097
120.( )
. 338 0 879, .
Confidence interval: 0.738 ↔ 0.879There is evidence to support the gardener’s claim that less than 90% of the seeds germinate because, based on the sample data, any values in the range 73.8% − 87.9% are possible values for the proportion of seeds in the sample that germinate.P = 0.9 is not in the confidence interval. At the 5% significance level, we accept the alternative hypothesis and agree that the gardener’s suspicions are well-founded.
61Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)Given: Three parallel lines AB, CD and EF such that C is on AE and D is on BF with |AC| = |CE|.
to prove: |BD| = |DF|.construction: Draw a line GH through D parallel to AE such that G is on AB and H is on EF.
proof: ACDG is a parallelogram ⇒ = =AC GD CE
CEHD is a parallelogram ⇒ =CE DH
∴ =GD DH
Now triangle GDB and triangle FDH are congruent (ASA) because:
∠ = ∠ =BGD FHD X [Alternate angles]
∠ = ∠ =GDB FDH Y [Vertically opposite angles]
GD DH= [Already proved]
∴ =BD DF
A
F
D
E
C
B
G
H
X
Y
Y
X
A
F
D
E
C
B
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
G: Germinate, NG: Not germinateP(G) = 0.6, P(NG) = 0.4
P(G, G, G, G) = = =( . )( . )( . )( . ) ( . )0 6 0 6 0 6 0 6 0 6 81625
4
P(G, NG, NG, NG) = × =( . )( . )( . )( . ) !!
0 6 0 4 0 4 0 4 43
96625
P(NG, NG, NG, NG) = = =( . )( . )( . )( . ) ( . )0 4 0 4 0 4 0 4 0 4 16625
4
Independence is necessary to do the calculation in (a) as the probability would change depending on whether or not the other seeds germinate. Independence may not be valid as the growing conditions (temperature, moisture and soil type) may vary from seed to seed.
Expected value = xP(x) = 4(0.6) = 2.4
Question 5 (25 marks)
Question 5 (a) (i)
Question 5 (a) (ii)
Question 5 (a) (iii)
Question 5 (b)
Question 5 (c)
Question 5 (d)Null hypothesis Ho: P = 0.9Alternative hypothesis H1: P < 0.9
Sample proportion = p = 97120
True population proportion = Sample proportion ± 1.96(Standard error of the proportion)
Standard error of the proportion = -p pn
( )1
True population proportion = ±-
=97120
1 961120
0 797
12097
120.( )
. 338 0 879, .
Confidence interval: 0.738 ↔ 0.879There is evidence to support the gardener’s claim that less than 90% of the seeds germinate because, based on the sample data, any values in the range 73.8% − 87.9% are possible values for the proportion of seeds in the sample that germinate.P = 0.9 is not in the confidence interval. At the 5% significance level, we accept the alternative hypothesis and agree that the gardener’s suspicions are well-founded.
Sample 3
Paper 2
62 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
400
100 200 300 400 500 6000
100
200
300
800
500
600
700
Fore
ign I
ncom
e (
Bil
lions o
f euro
)
Domestic Income (Billions of euro)
700
1000
900
1100
1200
( , )x y
Question 7 (75 marks)Question 7 (a)
CaSio CaLCuLator (fx-85GT PLUS)Steps to find r:Press Mode.Press 2: StatPress 2: A + BxInput your x and y valuesPress AC ButtonPress Shift followed by the Number 1Press 5: RegPress 3: rPress =
r = 0.6378
Question 7 (b)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (b)
x y y xx y x y y x
x xxx y
+ = ⇒ = −
= ⇒ = = =−
∴ = −=
∴ = =
5 5
4 646
23
2 53
3 10 25 10
2 3
( )
,
4
m
n
12
l
x
y
z
w6
z w z wxy
zw
ww
w w w
w
+ = ⇒ = −
=
=−
⇒ = − ⇒ =
∴ =
13 13
23
13 2 39 3 5 39
39
( )Pythagoras
55265
, z =
63Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
400
100 200 300 400 500 6000
100
200
300
800
500
600
700
Fore
ign I
ncom
e (
Bil
lions o
f euro
)
Domestic Income (Billions of euro)
700
1000
900
1100
1200
( , )x y
Question 7 (75 marks)Question 7 (a)
CaSio CaLCuLator (fx-85GT PLUS)Steps to find r:Press Mode.Press 2: StatPress 2: A + BxInput your x and y valuesPress AC ButtonPress Shift followed by the Number 1Press 5: RegPress 3: rPress =
r = 0.6378
Question 7 (b)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
Question 6 (b)
x y y xx y x y y x
x xxx y
+ = ⇒ = −
= ⇒ = = =−
∴ = −=
∴ = =
5 5
4 646
23
2 53
3 10 25 10
2 3
( )
,
4
m
n
12
l
x
y
z
w6
z w z wxy
zw
ww
w w w
w
+ = ⇒ = −
=
=−
⇒ = − ⇒ =
∴ =
13 13
23
13 2 39 3 5 39
39
( )Pythagoras
55265
, z =
Sample 3
Paper 2
64 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
400
100 200 300 400 500 6000
100
200
300
800
500
600
700
Fore
ign I
ncom
e (
Bil
lions o
f euro
)
Domestic Income (Billions of euro)
700
1000
900
1100
1200
( , )x y
The slope is now negative, there is a negative moderate correlation. The difference is that as domestic yearly income increases the foreign yearly income decreases.
Question 7 (f) (iii)
Question 7 (f) (iv)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
r = –0.5085
y yr
x x
y x
y
y
x
= + −
= +−
−
= −
σσ
( )
( . ) ( )
. (
442 0 5085 16054
230
442 1 51 xxy xy x
−= − += − +
230442 1 51 347 3
1 51 789 3
). .
. .
Slope m = −1.5
Question 7 (e) (iii) Question 7 (f) (i)
Question 7 (f) (ii)
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 5: RegPress 3: rPress = [Write down the answer]
x
y
=+ + + + + + + + +
=
=+ +
150 170 180 200 250 260 280 320 600 26010
267
400 580 7000 380 500 200 400 220 1200 60010
518
267 518
+ + + + + + +=
=( , ) ( , )x y
( , ) ( , ), ( , ) ( , )
.
x y x y
m
= =
=−−
=
267 518 600 10001000 518600 267
1 4
2 2
As the yearly domestic income increases the foreign yearly income increases.
Outlier (600, 1200); Possible answer: A boom for the economy due to a huge tourist influx and a huge increase in computer/pharmaceutical exports due to the exchange rate of the euro.
Question 7 (c)
Question 7 (d)
Question 7 (e)Remove (600, 1200) from the table and input the results again into your calculator. After pressing the AC button do the following:
x
x
==23054σ
y
y
==442160σ
Question 7 (e) (i) Question 7 (e) (ii)
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 4: VarPress 2: xPress = [Write down the answer]Press Shift followed by the Number 1Press 4: VarPress 3: σ xPress = [Write down the answer]
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 4: VarPress 3: yPress = [Write down the answer]Press Shift followed by the Number 1Press 4: VarPress 3: σ yPress = [Write down the answer]
65Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
400
100 200 300 400 500 6000
100
200
300
800
500
600
700
Fore
ign I
ncom
e (
Bil
lions o
f euro
)
Domestic Income (Billions of euro)
700
1000
900
1100
1200
( , )x y
The slope is now negative, there is a negative moderate correlation. The difference is that as domestic yearly income increases the foreign yearly income decreases.
Question 7 (f) (iii)
Question 7 (f) (iv)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
r = –0.5085
y yr
x x
y x
y
y
x
= + −
= +−
−
= −
σσ
( )
( . ) ( )
. (
442 0 5085 16054
230
442 1 51 xxy xy x
−= − += − +
230442 1 51 347 3
1 51 789 3
). .
. .
Slope m = −1.5
Question 7 (e) (iii) Question 7 (f) (i)
Question 7 (f) (ii)
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 5: RegPress 3: rPress = [Write down the answer]
x
y
=+ + + + + + + + +
=
=+ +
150 170 180 200 250 260 280 320 600 26010
267
400 580 7000 380 500 200 400 220 1200 60010
518
267 518
+ + + + + + +=
=( , ) ( , )x y
( , ) ( , ), ( , ) ( , )
.
x y x y
m
= =
=−−
=
267 518 600 10001000 518600 267
1 4
2 2
As the yearly domestic income increases the foreign yearly income increases.
Outlier (600, 1200); Possible answer: A boom for the economy due to a huge tourist influx and a huge increase in computer/pharmaceutical exports due to the exchange rate of the euro.
Question 7 (c)
Question 7 (d)
Question 7 (e)Remove (600, 1200) from the table and input the results again into your calculator. After pressing the AC button do the following:
x
x
==23054σ
y
y
==442160σ
Question 7 (e) (i) Question 7 (e) (ii)
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 4: VarPress 2: xPress = [Write down the answer]Press Shift followed by the Number 1Press 4: VarPress 3: σ xPress = [Write down the answer]
CaSio CaLCuLator (fx-85GT PLUS)Press Shift followed by the Number 1Press 4: VarPress 3: yPress = [Write down the answer]Press Shift followed by the Number 1Press 4: VarPress 3: σ yPress = [Write down the answer]
Sample 3
Paper 2
66 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P tt
t t
= + ==
= ⇒ = = =−
100 20 6 11020 6 10
6 6 603
12
1 12
coscos
cos cos ( ) o π
AS
CT
63
73
53
113
187
t
t
=
=
=
π π
π π
π
, [ ]
, [ ]
,
First quadrant
Fourth quadrant
ππ
π π18
518
1118
= ,
P tdPdt
t t
dPdt t
= +
= − × = −
= −=
100 20 6
20 6 6 120 6
1200
cos
sin sin
sinn ( )
sin sin
6 0 0
120 615
120 25
15
=
= −
= −
=
dPdt t π
π π== −
= −
= −
=
114
120 65
120 65
5
mm Hg
dPdt t π
π πsin sin ==
= −
= − =
=
70 5
120 63
120 2 03
.
sin sin
mm Hg
mm HgdPdt t π
ππ
Question 8 (c) (ii)
63
73
53
113
187
t
t
=
=
=
π π
π π
π
, [ ]
, [ ]
,
First quadrant
Fourth quadrant
ππ
π π18
518
1118
= ,
Question 8 (d)
A
S
B
105
10
15
A: People with high blood pressureB: High level of cholesterol
People with high blood pressure and high level of cholesterol = 10
P
P
P
( )
( )
(
High BP
High level of cholesterol
High
= =
= =
1540
38
2540
58
BBP high level of cholesterol
High BP high l
and
or
)
(
= =1040
14
P eevel of cholesterol) = =3040
34
P A B
P A P B P A B
( )
( ) ( ) ( )
or
and
=
+ − = + − =
34
38
58
14
34
(b)
(c)
(d)
(e)
(f)
(a)
Question 9 (25 marks)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P tt
P
= +=
∴ = + =
100 20 66 1
100 20 1 120
cos: cos
( )Maximum value
mm Hg (SP)
90
t (s)
P (mm Hg)
80
100
110
120
�
4
�
12
�
6
�
3
7�
12
�
2
5�
12
2�
3
�
18
5�
18
7�
18
11�
18
Range = [80, 120]
Period =π3
Duration = π3
s
Number of beats per minute = = =60 180 5713π π
Question 8 (50 marks)Question 8 (a)
P tt
P
= += −
∴ = + − =
100 20 66 1
100 20 1 80
cos: cos
( )Minimum value
mm Hg (DP))
Question 8 (b) (i)
Question 8 (b) (iii) Question 8 (b) (iv)
Draw a line through P = 100 mm Hg and read off the times as shown above.
P = 110 mm Hg ⇒ =t π π π π18
518
718
1118
s s s s, , ,
Question 8 (c) (i)
t (s) 0 π12
π6
π4
π3
512π π
2712π 2
3π
P (mm Hg) 120 100 80 100 120 100 80 100 120
Question 8 (b) (ii)
67Higher Level, Educate.ie Sample 3, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P tt
t t
= + ==
= ⇒ = = =−
100 20 6 11020 6 10
6 6 603
12
1 12
coscos
cos cos ( ) o π
AS
CT
63
73
53
113
187
t
t
=
=
=
π π
π π
π
, [ ]
, [ ]
,
First quadrant
Fourth quadrant
ππ
π π18
518
1118
= ,
P tdPdt
t t
dPdt t
= +
= − × = −
= −=
100 20 6
20 6 6 120 6
1200
cos
sin sin
sinn ( )
sin sin
6 0 0
120 615
120 25
15
=
= −
= −
=
dPdt t π
π π== −
= −
= −
=
114
120 65
120 65
5
mm Hg
dPdt t π
π πsin sin ==
= −
= − =
=
70 5
120 63
120 2 03
.
sin sin
mm Hg
mm HgdPdt t π
ππ
Question 8 (c) (ii)
63
73
53
113
187
t
t
=
=
=
π π
π π
π
, [ ]
, [ ]
,
First quadrant
Fourth quadrant
ππ
π π18
518
1118
= ,
Question 8 (d)
A
S
B
105
10
15
A: People with high blood pressureB: High level of cholesterol
People with high blood pressure and high level of cholesterol = 10
P
P
P
( )
( )
(
High BP
High level of cholesterol
High
= =
= =
1540
38
2540
58
BBP high level of cholesterol
High BP high l
and
or
)
(
= =1040
14
P eevel of cholesterol) = =3040
34
P A B
P A P B P A B
( )
( ) ( ) ( )
or
and
=
+ − = + − =
34
38
58
14
34
(b)
(c)
(d)
(e)
(f)
(a)
Question 9 (25 marks)
LC HigHer LeveL SoLutionS SampLe paper 3 (© Educate.ie)
P tt
P
= +=
∴ = + =
100 20 66 1
100 20 1 120
cos: cos
( )Maximum value
mm Hg (SP)
90
t (s)
P (mm Hg)
80
100
110
120
�
4
�
12
�
6
�
3
7�
12
�
2
5�
12
2�
3
�
18
5�
18
7�
18
11�
18
Range = [80, 120]
Period =π3
Duration = π3
s
Number of beats per minute = = =60 180 5713π π
Question 8 (50 marks)Question 8 (a)
P tt
P
= += −
∴ = + − =
100 20 66 1
100 20 1 80
cos: cos
( )Minimum value
mm Hg (DP))
Question 8 (b) (i)
Question 8 (b) (iii) Question 8 (b) (iv)
Draw a line through P = 100 mm Hg and read off the times as shown above.
P = 110 mm Hg ⇒ =t π π π π18
518
718
1118
s s s s, , ,
Question 8 (c) (i)
t (s) 0 π12
π6
π4
π3
512π π
2712π 2
3π
P (mm Hg) 120 100 80 100 120 100 80 100 120
Question 8 (b) (ii)
Sample 3
Paper 2
68 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
( ) ( )
( ) ( )( )
2 3 4 2 04 0
4 4 2 3 2
2
2
2
− + − + =
− <
− − −
k x k xb ac
k kNo real roots:
<<
− + − + <
+ <+ <
016 8 16 24 0
16 016 0
2
2
k k kk kk k( )
k k k( ) ,+ = ⇒ = −16 0 16 0
ans: −16 < k < 0
Question 3 (25 marks)Question 3 (a) Question 3 (b)
x x
x xx x x
x xx x
x
+ + = −
+ = − +
+ = + +
− − =+ − =
5 19 1
5 19 15 19 2 1
3 18 03 6 0
2
2
( )
( )( )== −
= − − + = − + = −
= + = + =
3 6
3 3 4 3 2 1
6 6 49 6 7 13
,
:
:
Check solutions:
x
xans: x = −3
Question 2 (b) (i) Question 2 (b) (ii)
answer: (3, −2, 4)
loglog
(log ) log(log )(log )
lo
22
22
2
2 2
12 7
7 12 03 4 0
xx
x xx x
+ =
− + =− − =
∴ gglog
23
24
3 2 84 2 16
x xx x= ⇒ = =
∴ = ⇒ = =
2 3 207 233 3
x y zx y zx y z
− + =+ + =+ − =
.....( ).......( )
.........( )
(
123
11 2 42 3 5) ( ) : ....( )
( ) ( ) : ....( )( )+ + =− + = ×−
+ =
9 4 434 2 20 2
9 4 4
x zx z
x z 338 4 40
3
27 4 434 16 4
6 12 202
− − = −=
+ == ⇒ =
− + =∴ = −
x zx
zz z
yy
Question 2 (25 marks)Question 2 (a)
Let axb c
byc a
cza b
k
ax k b cby k c acz k a bax by cz
−=
−=
−=
= −= −= −+ + =
( )( )( )
kkb kc kc ka ka kb− + − + − = 0
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
z i z iz i z iz i
= − − ⇒ + += − + ⇒ + −
∴ + +
3 33 33
( )( )
( )
is a factoris a factor
(( )z iz z iz z i iz i iz zz z
+ − =
+ − + + − + + − =
+ + + =
+ + =
3 03 3 9 3 3 06 9 1 06 10 0
2 2
2
2
z i z i= − − ⇒ = − +3 3
ORRoots:Sum Product
− − − += −
=
− + =
∴ + + =
3 36
100
6 10 0
2
2
i iSP
z Sz Pz z
,
If z is a root of the cubic equation, its conjugate is also a root. This is because the coefficients in the cubic are all real. Therefore, z z2 6 10 0+ + = is a factor of the cubic equation.
az z bz z z azaz z bz az a z
3 2 2
3 2 3 2
22 40 6 10 422 40 6 4
+ + + = + + +
+ + + = + +
( )( )( ) ++ + +
∴ = + ⇒ =+ = ⇒ =
∴ + + + =
( )
(
10 24 4022 6 4 3
10 24 543 22 54 403 2
a za a
a b bz z z z22
43
6 10 3 4 03 3
+ + + == − − − + −
z zz i i
)( ), ,
Question 1 (25 marks)Question 1 (a) (i)
sample paper 4: paper 1
Question 1 (a) (ii)
Question 1 (b)
z a bi z a bi= + ⇒ = −
69Higher Level, Educate.ie Sample 4, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
( ) ( )
( ) ( )( )
2 3 4 2 04 0
4 4 2 3 2
2
2
2
− + − + =
− <
− − −
k x k xb ac
k kNo real roots:
<<
− + − + <
+ <+ <
016 8 16 24 0
16 016 0
2
2
k k kk kk k( )
k k k( ) ,+ = ⇒ = −16 0 16 0
ans: −16 < k < 0
Question 3 (25 marks)Question 3 (a) Question 3 (b)
x x
x xx x x
x xx x
x
+ + = −
+ = − +
+ = + +
− − =+ − =
5 19 1
5 19 15 19 2 1
3 18 03 6 0
2
2
( )
( )( )== −
= − − + = − + = −
= + = + =
3 6
3 3 4 3 2 1
6 6 49 6 7 13
,
:
:
Check solutions:
x
xans: x = −3
Question 2 (b) (i) Question 2 (b) (ii)
answer: (3, −2, 4)
loglog
(log ) log(log )(log )
lo
22
22
2
2 2
12 7
7 12 03 4 0
xx
x xx x
+ =
− + =− − =
∴ gglog
23
24
3 2 84 2 16
x xx x= ⇒ = =
∴ = ⇒ = =
2 3 207 233 3
x y zx y zx y z
− + =+ + =+ − =
.....( ).......( )
.........( )
(
123
11 2 42 3 5) ( ) : ....( )
( ) ( ) : ....( )( )+ + =− + = ×−
+ =
9 4 434 2 20 2
9 4 4
x zx z
x z 338 4 40
3
27 4 434 16 4
6 12 202
− − = −=
+ == ⇒ =
− + =∴ = −
x zx
zz z
yy
Question 2 (25 marks)Question 2 (a)
Let axb c
byc a
cza b
k
ax k b cby k c acz k a bax by cz
−=
−=
−=
= −= −= −+ + =
( )( )( )
kkb kc kc ka ka kb− + − + − = 0
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
z i z iz i z iz i
= − − ⇒ + += − + ⇒ + −
∴ + +
3 33 33
( )( )
( )
is a factoris a factor
(( )z iz z iz z i iz i iz zz z
+ − =
+ − + + − + + − =
+ + + =
+ + =
3 03 3 9 3 3 06 9 1 06 10 0
2 2
2
2
z i z i= − − ⇒ = − +3 3
ORRoots:Sum Product
− − − += −
=
− + =
∴ + + =
3 36
100
6 10 0
2
2
i iSP
z Sz Pz z
,
If z is a root of the cubic equation, its conjugate is also a root. This is because the coefficients in the cubic are all real. Therefore, z z2 6 10 0+ + = is a factor of the cubic equation.
az z bz z z azaz z bz az a z
3 2 2
3 2 3 2
22 40 6 10 422 40 6 4
+ + + = + + +
+ + + = + +
( )( )( ) ++ + +
∴ = + ⇒ =+ = ⇒ =
∴ + + + =
( )
(
10 24 4022 6 4 3
10 24 543 22 54 403 2
a za a
a b bz z z z22
43
6 10 3 4 03 3
+ + + == − − − + −
z zz i i
)( ), ,
Question 1 (25 marks)Question 1 (a) (i)
sample paper 4: paper 1
Question 1 (a) (ii)
Question 1 (b)
z a bi z a bi= + ⇒ = −
Sample 4
Paper 1
70 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is an injective function which means that every y value has its own unique matching x value.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a bijective function as there is a perfect one to one correspondence between the x and y values. A bijective function means it is both an injective and surjective function.
Question 5 (c)
Domain = {0, 1, 2, 3, 4, 5,....}Range = {0, 1, 4, 9, 16,.......}Every element in the domain matches to a unique element in the range. There are elements in the range that do not have a matching element from the domain.
Question 5 (d)
Domain = {Positive real numbers}Range = {Positive real numbers}Every element in the domain matches to a unique element in the range. Every element in the range has a unique matching element from the domain.
✓
✓
✓
✓
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a surjective function which means that every y value has at least one matching x value. It is not injective as many y values have more than one correspoding x value.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is not a function because x values have two y values.
Question 5 (e)
Domain = {All real numbers}Range = {Positive real numbers}Every element in the domain matches to at least one element in the range. Some values in the range match to two elements in the range. For example, 22 and (−2)2 both map on to 4.
x
y
Question 5 (f)
✓
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
11
11
132
13
19
127
13
13
, , , ,.......,a r
S ar
= =
=−
=−
=∞
a d a a da d a a d a a
d dd d
− +− + + + = = ⇒ =
− +
− + + + =
, ,
, ,( ) ( )
3 27 9
9 9 99 9 9 293
8
2 2 2
11 18 81 81 18 2932 293 2432 50
255
2 2
2
2
2
− + + + + + =
= −
=
== ±
d d d ddddd (Use eitther)
Numbers: 4, 9, 14
Question 4 (25 marks)Question 4 (a) Question 4 (b)
Question 5 (25 marks)
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a bijective function as there is a perfect one to one correspondence between the x and y values. A bijective function means it is both an injective and surjective function.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a surjective function which means that every y value has at least one matching x value. It is not injective as many y values have more than one corresponding x value.
x
y
y f x= ( )
x
y
y g x= ( )
Question 5 (a)
Question 5 (b)
✓
✓
✓
✓
71Higher Level, Educate.ie Sample 4, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is an injective function which means that every y value has its own unique matching x value.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a bijective function as there is a perfect one to one correspondence between the x and y values. A bijective function means it is both an injective and surjective function.
Question 5 (c)
Domain = {0, 1, 2, 3, 4, 5,....}Range = {0, 1, 4, 9, 16,.......}Every element in the domain matches to a unique element in the range. There are elements in the range that do not have a matching element from the domain.
Question 5 (d)
Domain = {Positive real numbers}Range = {Positive real numbers}Every element in the domain matches to a unique element in the range. Every element in the range has a unique matching element from the domain.
✓
✓
✓
✓
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a surjective function which means that every y value has at least one matching x value. It is not injective as many y values have more than one correspoding x value.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is not a function because x values have two y values.
Question 5 (e)
Domain = {All real numbers}Range = {Positive real numbers}Every element in the domain matches to at least one element in the range. Some values in the range match to two elements in the range. For example, 22 and (−2)2 both map on to 4.
x
y
Question 5 (f)
✓
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
11
11
132
13
19
127
13
13
, , , ,.......,a r
S ar
= =
=−
=−
=∞
a d a a da d a a d a a
d dd d
− +− + + + = = ⇒ =
− +
− + + + =
, ,
, ,( ) ( )
3 27 9
9 9 99 9 9 293
8
2 2 2
11 18 81 81 18 2932 293 2432 50
255
2 2
2
2
2
− + + + + + =
= −
=
== ±
d d d ddddd (Use eitther)
Numbers: 4, 9, 14
Question 4 (25 marks)Question 4 (a) Question 4 (b)
Question 5 (25 marks)
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a bijective function as there is a perfect one to one correspondence between the x and y values. A bijective function means it is both an injective and surjective function.
injeCtive FunCtion
SurjeCtive FunCtion
BijeCtive FunCtion
This is a surjective function which means that every y value has at least one matching x value. It is not injective as many y values have more than one corresponding x value.
x
y
y f x= ( )
x
y
y g x= ( )
Question 5 (a)
Question 5 (b)
✓
✓
✓
✓
Sample 4
Paper 1
72 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Height of player + arm span above head = 1.85 m + 0.8 m = 2.65 my t tt y= − −= =
3 3 13 4 90 3 3
2. .: . m
Height above base of racket = 3.3 − 2.65 = 0.65 m
y t ty t t
t
= − −
= + − =
=− ± − −
3 3 13 4 90 4 9 13 3 3 0
13 13 4 4 9 3 32
2
2
2 2
. .: . .
( . )( . )(( . )
.4 9
0 23= s
x tt x== = =
700 23 70 0 23 16 1. : ( . ) . m
Distance from baseline to far serve line = 11.885 m + 6.4 m = 18.285 mBall is in as 16.1 m < 18.285 m
x tx t t== = ⇒ =
7011 885 11 885 70 0 17. : . . s
y t ty t tt t
= − −
= = − −
+ − =
3 3 13 4 90 914 0 914 3 3 13 4 9
4 9 13 2 386
2
2
2
. .
. : . . .. . 00
13 13 4 4 9 2 3862 4 9
0 1722
t =− ± −
=( . )( . )
( . ). s
x btt b b== = ⇒ =0 172 11 885 0 172 69 1. : . ( . ) .
Question 7 (50 marks)
6.4 mO
Service line
11.885 m
Net
B
0.914 m
( , )x y
A
C
Question 7 (a)
Question 7 (b)
Question 7 (c)
Question 7 (d)
Question 7 (e)y t tt y= − −
= = − − =
3 3 13 4 90 17 3 3 13 0 17 4 9 0 17 0 948
2
2
. .. : . ( . ) . ( . ) .s m
Yes, it will clear the net.
Question 7 (f) (i) Question 7 (f) (ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Question 6 (25 marks)
f (x) is continuous as there are no gaps.g(x) is not continuous at there is a gap at x = 0.
y f x x xf x xf x xx
= = − + +′ = − +′ = ⇒ − + =
− +
( )( )( )
76
2 176
313
73
176
73
1760 0
14 117 01714
=∴ =x
y f x x x
y x x
x xx
= = − + +
= ⇒ − + + =
− − =−
( )
(
76
2 176
313
76
2 176
313
2
0 0
7 17 62 07 311 2 0
22 0 0
317
317
)( ),
( , ), ( , )
xxA B
+ == −
∴ −
y
x
y f x= ( )
y g x= ( )
y g x= ( )
A
C
D
B
Question 6 (a)
Question 6 (b)
Question 6 (c)
Question 6 (d)
Question 6 (e)
( , ) ( )?( )
( ) ( ) ( )
1 12
1 1 1
76
2 176
313
76
2 176
313
76
∈
= − + +
= − + +
= −
f xf x x x
f++ + = =
∈
=
= =
176
313
363 12
1 1212
1 121
12
( )
( , ) ( )?
( )
( ) (
True
True
g x
g xx
g ))
( , ) ( )?( )
( ) ( ) ( )
4 3
4 4 4
76
2 176
313
76
2 176
313
563
∈
= − + +
= − + +
= −
f xf x x x
f++ + = =
∈
=
= =
343
313
93 3
4 312
4 124
3
( )
( , ) ( )?
( )
( ) ( )
True
True
g x
g xx
g
A f x g x dx
x xxdx
x
= −
= − + + −
= − +
∫
∫
( ( ) ( ))
[
1
4
76
2 176
3131
4
718
3 1
12
7712
2 313 1
4
718
3 1712
2 313
12
4 4 4 12 4
x x x+ −
= − + + − − −
ln ]
{ ( ) ( ) ( ) ln( )} { 7718
3 1712
2 313
1114
1 1 1 12 112 4 11 1
( ) ( ) ( ) ln( )}ln .
+ + −
= − ≈
73Higher Level, Educate.ie Sample 4, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Height of player + arm span above head = 1.85 m + 0.8 m = 2.65 my t tt y= − −= =
3 3 13 4 90 3 3
2. .: . m
Height above base of racket = 3.3 − 2.65 = 0.65 m
y t ty t t
t
= − −
= + − =
=− ± − −
3 3 13 4 90 4 9 13 3 3 0
13 13 4 4 9 3 32
2
2
2 2
. .: . .
( . )( . )(( . )
.4 9
0 23= s
x tt x== = =
700 23 70 0 23 16 1. : ( . ) . m
Distance from baseline to far serve line = 11.885 m + 6.4 m = 18.285 mBall is in as 16.1 m < 18.285 m
x tx t t== = ⇒ =
7011 885 11 885 70 0 17. : . . s
y t ty t tt t
= − −
= = − −
+ − =
3 3 13 4 90 914 0 914 3 3 13 4 9
4 9 13 2 386
2
2
2
. .
. : . . .. . 00
13 13 4 4 9 2 3862 4 9
0 1722
t =− ± −
=( . )( . )
( . ). s
x btt b b== = ⇒ =0 172 11 885 0 172 69 1. : . ( . ) .
Question 7 (50 marks)
6.4 mO
Service line
11.885 m
Net
B
0.914 m
( , )x y
A
C
Question 7 (a)
Question 7 (b)
Question 7 (c)
Question 7 (d)
Question 7 (e)y t tt y= − −
= = − − =
3 3 13 4 90 17 3 3 13 0 17 4 9 0 17 0 948
2
2
. .. : . ( . ) . ( . ) .s m
Yes, it will clear the net.
Question 7 (f) (i) Question 7 (f) (ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Question 6 (25 marks)
f (x) is continuous as there are no gaps.g(x) is not continuous at there is a gap at x = 0.
y f x x xf x xf x xx
= = − + +′ = − +′ = ⇒ − + =
− +
( )( )( )
76
2 176
313
73
176
73
1760 0
14 117 01714
=∴ =x
y f x x x
y x x
x xx
= = − + +
= ⇒ − + + =
− − =−
( )
(
76
2 176
313
76
2 176
313
2
0 0
7 17 62 07 311 2 0
22 0 0
317
317
)( ),
( , ), ( , )
xxA B
+ == −
∴ −
y
x
y f x= ( )
y g x= ( )
y g x= ( )
A
C
D
B
Question 6 (a)
Question 6 (b)
Question 6 (c)
Question 6 (d)
Question 6 (e)
( , ) ( )?( )
( ) ( ) ( )
1 12
1 1 1
76
2 176
313
76
2 176
313
76
∈
= − + +
= − + +
= −
f xf x x x
f++ + = =
∈
=
= =
176
313
363 12
1 1212
1 121
12
( )
( , ) ( )?
( )
( ) (
True
True
g x
g xx
g ))
( , ) ( )?( )
( ) ( ) ( )
4 3
4 4 4
76
2 176
313
76
2 176
313
563
∈
= − + +
= − + +
= −
f xf x x x
f++ + = =
∈
=
= =
343
313
93 3
4 312
4 124
3
( )
( , ) ( )?
( )
( ) ( )
True
True
g x
g xx
g
A f x g x dx
x xxdx
x
= −
= − + + −
= − +
∫
∫
( ( ) ( ))
[
1
4
76
2 176
3131
4
718
3 1
12
7712
2 313 1
4
718
3 1712
2 313
12
4 4 4 12 4
x x x+ −
= − + + − − −
ln ]
{ ( ) ( ) ( ) ln( )} { 7718
3 1712
2 313
1114
1 1 1 12 112 4 11 1
( ) ( ) ( ) ln( )}ln .
+ + −
= − ≈
Sample 4
Paper 1
74 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
y mx cy t b a
c aa a
m
= += +
=
= ⇒ = =
log log log
log
. log .
10 10 10
10
102 62 6 10 398
==
=−
log( , . ), ( , . )
. .
10
3 2 875 6 3 1553 155 2 875
6
b
m
Points on graph:
−−=
= ⇒ = =3
0 093
0 093 10 1 24100 093
.
. log ..b b
398
y ab
t
t
t
t
=
= ×
=
=
2200 398 1 242200398
1 24
2200398
110 10
.
.
log log ..
log
log ..
24
22003981 24
7 9 810
10
∴ =
= ≈t years
Question 8 (c)
Question 8 (d)
Question 8 (e)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
t (Number of years after 2006) 1 2 3 4 5 6y (Cost ) 500 610 720 890 1050 1540log10 y 2.70 2.79 2.86 2.95 3.02 3.19
y aby aby a by a t
t
t
t
=
=
= += +
log log ( )
log log loglog log
10 10
10 10 10
10 10 llog10 b
1 2 3 4 5 6 t (years)0
2.00
1.00
2.875
log10
y
4.00
3.00
3.155
2.600
Question 8 (50 marks)Question 8 (a)
Question 8 (b) (i)
Question 8 (b) (ii)
75Higher Level, Educate.ie Sample 4, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
y mx cy t b a
c aa a
m
= += +
=
= ⇒ = =
log log log
log
. log .
10 10 10
10
102 62 6 10 398
==
=−
log( , . ), ( , . )
. .
10
3 2 875 6 3 1553 155 2 875
6
b
m
Points on graph:
−−=
= ⇒ = =3
0 093
0 093 10 1 24100 093
.
. log ..b b
398
y ab
t
t
t
t
=
= ×
=
=
2200 398 1 242200398
1 24
2200398
110 10
.
.
log log ..
log
log ..
24
22003981 24
7 9 810
10
∴ =
= ≈t years
Question 8 (c)
Question 8 (d)
Question 8 (e)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
t (Number of years after 2006) 1 2 3 4 5 6y (Cost ) 500 610 720 890 1050 1540log10 y 2.70 2.79 2.86 2.95 3.02 3.19
y aby aby a by a t
t
t
t
=
=
= += +
log log ( )
log log loglog log
10 10
10 10 10
10 10 llog10 b
1 2 3 4 5 6 t (years)0
2.00
1.00
2.875
log10
y
4.00
3.00
3.155
2.600
Question 8 (50 marks)Question 8 (a)
Question 8 (b) (i)
Question 8 (b) (ii)
Sample 4
Paper 1
76 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
x y mx y m+ − = ⇒ = −+ − = ⇒ = −
= +− − −+ − −
=
−
3 0 12 1 0 2
1 21 1 2
1
2
tan ( )( )( )
θ11 2
1 213
18 41 13
++
=
∴ = =−θ tan ( ) . o
θ = tan 3�1
(4, 1)�
m m1=
m2= 2
θ θ= ⇒ =− − = ⇒ =
= ±−+
∴ + = −
−tan tan
( ) ( )
1
2
3 32 8 0 2
3 21 2
3 1 2 2
x y mmm
m m33 6 25 5
1
+ = −= −= −
m mmm
Equations of line:
l m x y kl k k
l x y
l m x
1
1
1
217
1 04 1 4 1 0 3
3 0
:( , )
:
:
= − ⇒ + + =− ∈ ⇒ − + = ⇒ = −+ − =
= − ⇒ + 77 04 1 4 7 0 3
7 3 02
2
y kl k k
l x y
+ =
− ∈ ⇒ − + = ⇒ =+ + =
( , ):
sample paper 4: paper 2Question 1 (25 marks)
tanθ = ± −+
m mm m
1 2
1 21
∴ + = − −+ = − += −= −
3 1 2 23 6 27 1
17
( ) ( )m mm m
mm
Question 1 (b)
Question 1 (a)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Question 9 (50 marks)Question 9 (a) (i)h = 1 + x
r
1
O
A B
h
x
1
x r
r x
2 2 2
2
1
1
+ =
= −
V r h
x x
x x x
=
= − +
= + − +
13
2
13
2
13
2 3
1 1
1
p
p
p
( )( )
( )
V x x xdVdx
x x
x xx x
= + − −
= − − =
+ − =− + =
13
2 3
13
2
2
1
1 2 3 0
3 2 1 03 1 1
p
p
( )
( )
( )( ) 00
1
1
13
13
13
13
2 13
3 3281
x
V
= −
∴ = + − − =
,
( ( ) ( ) ( ) )Max. p p
xh x
r x
=
= + =
= − = − = =
13
43
2 13
2 89
23
1
1 1 2( )
O
A B
x
θ
1
r = 23 2
h = 43
Question 9 (a) (ii)
Question 9 (b)
Question 9 (c) Question 9 (d)
Cone: cm s
Sphere: cm s
dVdtdVdt
V h hdVdh
= −
= +
= −
=
−
−
0 2
0 2
3 1
3 1
2 13
3
.
.
p p
22
2
0 2 2
2
2
0 3
p p
p p
h h
dVdt
dVdh
dhdt
h h dhdt
dVdt h
−
= × = −
= =
=
( )
. [.
pp p
p p
( . ) ( . ) ]
.[ ( . ) ( . ) ]
.
0 3 0 3
0 22 0 3 0 3
0 125
2
21
−
∴ =−
= −
dhdt
dhdt
cms
1
h
Question 9 (e)
tan
tan
θ
θ
= = =
=
≈
−
rh
23
43
1
2 12
12
35o
77Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
x y mx y m+ − = ⇒ = −+ − = ⇒ = −
= +− − −+ − −
=
−
3 0 12 1 0 2
1 21 1 2
1
2
tan ( )( )( )
θ11 2
1 213
18 41 13
++
=
∴ = =−θ tan ( ) . o
θ = tan 3�1
(4, 1)�
m m1=
m2= 2
θ θ= ⇒ =− − = ⇒ =
= ±−+
∴ + = −
−tan tan
( ) ( )
1
2
3 32 8 0 2
3 21 2
3 1 2 2
x y mmm
m m33 6 25 5
1
+ = −= −= −
m mmm
Equations of line:
l m x y kl k k
l x y
l m x
1
1
1
217
1 04 1 4 1 0 3
3 0
:( , )
:
:
= − ⇒ + + =− ∈ ⇒ − + = ⇒ = −+ − =
= − ⇒ + 77 04 1 4 7 0 3
7 3 02
2
y kl k k
l x y
+ =
− ∈ ⇒ − + = ⇒ =+ + =
( , ):
sample paper 4: paper 2Question 1 (25 marks)
tanθ = ± −+
m mm m
1 2
1 21
∴ + = − −+ = − += −= −
3 1 2 23 6 27 1
17
( ) ( )m mm m
mm
Question 1 (b)
Question 1 (a)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Question 9 (50 marks)Question 9 (a) (i)h = 1 + x
r
1
O
A B
h
x
1
x r
r x
2 2 2
2
1
1
+ =
= −
V r h
x x
x x x
=
= − +
= + − +
13
2
13
2
13
2 3
1 1
1
p
p
p
( )( )
( )
V x x xdVdx
x x
x xx x
= + − −
= − − =
+ − =− + =
13
2 3
13
2
2
1
1 2 3 0
3 2 1 03 1 1
p
p
( )
( )
( )( ) 00
1
1
13
13
13
13
2 13
3 3281
x
V
= −
∴ = + − − =
,
( ( ) ( ) ( ) )Max. p p
xh x
r x
=
= + =
= − = − = =
13
43
2 13
2 89
23
1
1 1 2( )
O
A B
x
θ
1
r = 23 2
h = 43
Question 9 (a) (ii)
Question 9 (b)
Question 9 (c) Question 9 (d)
Cone: cm s
Sphere: cm s
dVdtdVdt
V h hdVdh
= −
= +
= −
=
−
−
0 2
0 2
3 1
3 1
2 13
3
.
.
p p
22
2
0 2 2
2
2
0 3
p p
p p
h h
dVdt
dVdh
dhdt
h h dhdt
dVdt h
−
= × = −
= =
=
( )
. [.
pp p
p p
( . ) ( . ) ]
.[ ( . ) ( . ) ]
.
0 3 0 3
0 22 0 3 0 3
0 125
2
21
−
∴ =−
= −
dhdt
dhdt
cms
1
h
Question 9 (e)
tan
tan
θ
θ
= = =
=
≈
−
rh
23
43
1
2 12
12
35o Sample 4
Paper 2
78 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
AB
CD
q
p
k
h
θ
AB
CD
qp
k
h
h
CD k
θ 180o −θ
The adjacent interior angles in a parallelogram add up to 180o.
cos( ) cos cos sin sin( ) cos ( )sin
cos
180 180 1801 0
o o o− = −= − −= −
θ θ θθ θ
θ
p h k kh
q h k khq h k kh
2 2 2
2 2 2
2 2 2
2
2 1802
= + −
= + − −
= + +
cos ....( )
cos( )
θ
θ
1
o
ccos ....( )θ 2
∴ + = +p q h k2 2 2 22 2
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
Question 3 (c)
Add equations (1) and (2):
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
s
r =5
2(1, 2)
( 2, 6)�
r = 5
s x y x y
r
:
( , ),
2 2
2 2
2 4 20 0
1 2 1 2 20 25 5
+ − − − =
= + + = =Centre
Radius of new circle: r = 52
Centre of new circle is midpoint of (1, 2) and (−2, 6).
Centre = − + +
= −
2 12
6 22
412, ( , )
Equation of new circle: ( ) ( ) ( )x y
x x y y
x y x y
+ + − =
+ + + − + =
+ + − + =
12
2 2 52
2
2 14
2 254
2 2
4
8 16
8 10 0
Question 2 (25 marks)
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
79Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
AB
CD
q
p
k
h
θ
AB
CD
qp
k
h
h
CD k
θ 180o −θ
The adjacent interior angles in a parallelogram add up to 180o.
cos( ) cos cos sin sin( ) cos ( )sin
cos
180 180 1801 0
o o o− = −= − −= −
θ θ θθ θ
θ
p h k kh
q h k khq h k kh
2 2 2
2 2 2
2 2 2
2
2 1802
= + −
= + − −
= + +
cos ....( )
cos( )
θ
θ
1
o
ccos ....( )θ 2
∴ + = +p q h k2 2 2 22 2
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
Question 3 (c)
Add equations (1) and (2):
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
s
r =5
2(1, 2)
( 2, 6)�
r = 5
s x y x y
r
:
( , ),
2 2
2 2
2 4 20 0
1 2 1 2 20 25 5
+ − − − =
= + + = =Centre
Radius of new circle: r = 52
Centre of new circle is midpoint of (1, 2) and (−2, 6).
Centre = − + +
= −
2 12
6 22
412, ( , )
Equation of new circle: ( ) ( ) ( )x y
x x y y
x y x y
+ + − =
+ + + − + =
+ + − + =
12
2 2 52
2
2 14
2 254
2 2
4
8 16
8 10 0
Question 2 (25 marks)
Centre Radius( , ),( ) ( )
h k rx h y k r− + − =2 2 2
Sample 4
Paper 2
80 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
x 1 2 3 4 5P(x) 0.1 0.2 0.3 0.3 0.1
P P P( ) [ ( ) ( )]. . .
At least 3 1 1 21 0 1 0 2 0 7
= − += − − =
xxP xP
= =+ + + +
+ + +∑∑
( ) ( . ) ( . ) ( . ) ( . ) ( . ). . .
9 0 1 2 0 2 3 0 3 4 0 3 5 0 10 1 0 2 0 3 0.. .
.3 0 1
3 1+
=
Gender For Against TotalMale 58 85 143Female 84 73 157Total 142 158 300
P( )Male Against treatyand = =85300
1760
P( )Female For treatyor =+
=58 157
3004360
Question 5 (25 marks)
Question 5 (a) (i)
Question 5 (a) (ii)
Question 5 (b) (ii)
Question 5 (b) (i)
Question 5 (b) (iii)
OrP(3) + P(4) + P(5) = 0.3 + 0.3 + 0.1 = 0.7
P = =58
1422971
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Height
µ = 175LQ = 170 UQ = 180
(i) Median M = 175 cm(ii) Lower quartile (LQ) = 170 cm(iii) Interquartile range = 180 − 170 = 10 cm
P xP z Z z
x z x
( ) .( ) . .
: .
≤ =≤ = ⇒ =
= =−
⇒ =−
180 0 750 75 0 675
180 0 675 180 175µσ σσ
σ∴ =−
=180 175
0 6757 4
.. cm
x z
x z
P x
= =−
= −
= =−
=
≤ ≤
170 170 1757 4
0 675
180 180 1757 4
0 675
170 1
:.
.
:.
.
( 8800 675 0 675
0 675 0 6750 675
)( . . )( . ) ( . )( . ) {
= − ≤ ≤= ≤ − ≤ −= ≤ −
P zP z P zP z 11 0 6752 0 675 12 0 75 11 5 10 5
− ≤= ≤ −= −= −=
P zP z
( . )}( . )
( . )..
Question 4 (25 marks)
Question 4 (a)
75% of students have a height less than 180 cm.Question 4 (b)
Question 4 (c)
Question 4 (d)
81Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
x 1 2 3 4 5P(x) 0.1 0.2 0.3 0.3 0.1
P P P( ) [ ( ) ( )]. . .
At least 3 1 1 21 0 1 0 2 0 7
= − += − − =
xxP xP
= =+ + + +
+ + +∑∑
( ) ( . ) ( . ) ( . ) ( . ) ( . ). . .
9 0 1 2 0 2 3 0 3 4 0 3 5 0 10 1 0 2 0 3 0.. .
.3 0 1
3 1+
=
Gender For Against TotalMale 58 85 143Female 84 73 157Total 142 158 300
P( )Male Against treatyand = =85300
1760
P( )Female For treatyor =+
=58 157
3004360
Question 5 (25 marks)
Question 5 (a) (i)
Question 5 (a) (ii)
Question 5 (b) (ii)
Question 5 (b) (i)
Question 5 (b) (iii)
OrP(3) + P(4) + P(5) = 0.3 + 0.3 + 0.1 = 0.7
P = =58
1422971
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Height
µ = 175LQ = 170 UQ = 180
(i) Median M = 175 cm(ii) Lower quartile (LQ) = 170 cm(iii) Interquartile range = 180 − 170 = 10 cm
P xP z Z z
x z x
( ) .( ) . .
: .
≤ =≤ = ⇒ =
= =−
⇒ =−
180 0 750 75 0 675
180 0 675 180 175µσ σσ
σ∴ =−
=180 175
0 6757 4
.. cm
x z
x z
P x
= =−
= −
= =−
=
≤ ≤
170 170 1757 4
0 675
180 180 1757 4
0 675
170 1
:.
.
:.
.
( 8800 675 0 675
0 675 0 6750 675
)( . . )( . ) ( . )( . ) {
= − ≤ ≤= ≤ − ≤ −= ≤ −
P zP z P zP z 11 0 6752 0 675 12 0 75 11 5 10 5
− ≤= ≤ −= −= −=
P zP z
( . )}( . )
( . )..
Question 4 (25 marks)
Question 4 (a)
75% of students have a height less than 180 cm.Question 4 (b)
Question 4 (c)
Question 4 (d)
Sample 4
Paper 2
82 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Outcome Not a Prime Sum Prime Sum
P 712
512
Net income to Bob –3 3
xP(x) − 74
54
(i) A random variable is a function that associates a unique numerical value with every outcome of an experiment. It may vary from trial to trial as the experiment is repeated.(ii) DiSCrete: Ex. A coin is tossed five times. The random variable is the number of heads. Its values can be 0, 1, 2, 3, 4, 5. ContinuouS: Ex. The temperature in a house during the day can take any positive or negative value within a certain range.(iii) Expected value µ = =∑ xP x( ) Mean of a probability distribution.
(i) A prime number is a whole positive integer (excluding 1) divisible by itself and 1 only.
(ii)
4
5
6
1
3
2
Die A
Die
B
1
2
3
3 4 5 6
4 5 6 7 8
2 3 4 5 6 7
7 8 9 10 11 12
6 7 8 9 10 11
5 6 7 8 9 10
4 5 6 7 8 9
Primes in table: 2, 3, 5, 7, 11Number of primes = 15
P( )Sum that is a prime Number of primesNumber of numbers
= =15536
512
=
P( )Sum that is a prime Number of non-primesNumber of n
not =uumbers
= =2136
712
Question 7 (50 marks)Question 7 (a)
Question 7 (b)
(iii)
(iv)
Question 7 (c)
E xP x= = − + = −∑ ( ) 74
54
12
E = –50 c, on average Bob loses 50 c per game.
Expected losses: 30 1512× − = −( )
Question 7 (d)(i)
(ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
′ = −
→ − −
′ =
→ −
′ =
A
B
C
12
32
6 32
2 92
92
92
1
, ,
, ,
332
0 0 0
6 92
32
92
2712
12
, ( , )
( )
→
= −
− −
−
= −A −− = − =
274
1354
1358
12
AreaArea
′ ′ ′=
= =
=
A B CABC
k
1358
152
94
32
22
A B CA x y x y
( , ), ( , ), ( , )
( )( ) ( )( )
0 0 1 4 4 1
1 1 4 4
15
12 1 2 2 1
12
12
15
= −
= −
= −
= 22
kOAOA
= =′=
Image LengthObject Length
32
A(0, 0)
O( 1, 3)�
A’
3
2
1
A x y( , )1 1
a
b
B x y( , )2 2
C x y( , )
x ax bxa b
y ay bya b
=−−
=−−
2 1 2 1,
a bO x y A x y
A
= =− = =
′ =− −−
3 11 3 0 0
3 0 1 13 1
3 01 1 2 2
,( , ) ( , ); ( , ) ( , )
( ) ( ) , ( ) −−−
= −
= =− = =
1 33 1
12
32
3 11 3 1 41 1
( ) ,
,( , ) ( , ); ( , )a bO x y B (( , )
( ) ( ) , ( ) ( ) ,
,
x y
B
a
2 2
3 1 1 13 1
3 4 1 33 1
2 92
3
′ =− −−
−−
=
= bbO x y C x y
C
=− = =
′ =− −−
−
11 3 4 1
3 4 1 13 1
3 1 11 1 2 2( , ) ( , ); ( , ) ( , )
( ) ( ) , ( ) (333 1
132
0) ,−
=
Question 6 (25 marks)Question 6 (a)
Question 6 (b)
Question 6 (c)
external Division
83Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
Outcome Not a Prime Sum Prime Sum
P 712
512
Net income to Bob –3 3
xP(x) − 74
54
(i) A random variable is a function that associates a unique numerical value with every outcome of an experiment. It may vary from trial to trial as the experiment is repeated.(ii) DiSCrete: Ex. A coin is tossed five times. The random variable is the number of heads. Its values can be 0, 1, 2, 3, 4, 5. ContinuouS: Ex. The temperature in a house during the day can take any positive or negative value within a certain range.(iii) Expected value µ = =∑ xP x( ) Mean of a probability distribution.
(i) A prime number is a whole positive integer (excluding 1) divisible by itself and 1 only.
(ii)
4
5
6
1
3
2
Die A
Die
B
1
2
3
3 4 5 6
4 5 6 7 8
2 3 4 5 6 7
7 8 9 10 11 12
6 7 8 9 10 11
5 6 7 8 9 10
4 5 6 7 8 9
Primes in table: 2, 3, 5, 7, 11Number of primes = 15
P( )Sum that is a prime Number of primesNumber of numbers
= =15536
512
=
P( )Sum that is a prime Number of non-primesNumber of n
not =uumbers
= =2136
712
Question 7 (50 marks)Question 7 (a)
Question 7 (b)
(iii)
(iv)
Question 7 (c)
E xP x= = − + = −∑ ( ) 74
54
12
E = –50 c, on average Bob loses 50 c per game.
Expected losses: 30 1512× − = −( )
Question 7 (d)(i)
(ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
′ = −
→ − −
′ =
→ −
′ =
A
B
C
12
32
6 32
2 92
92
92
1
, ,
, ,
332
0 0 0
6 92
32
92
2712
12
, ( , )
( )
→
= −
− −
−
= −A −− = − =
274
1354
1358
12
AreaArea
′ ′ ′=
= =
=
A B CABC
k
1358
152
94
32
22
A B CA x y x y
( , ), ( , ), ( , )
( )( ) ( )( )
0 0 1 4 4 1
1 1 4 4
15
12 1 2 2 1
12
12
15
= −
= −
= −
= 22
kOAOA
= =′=
Image LengthObject Length
32
A(0, 0)
O( 1, 3)�
A’
3
2
1
A x y( , )1 1
a
b
B x y( , )2 2
C x y( , )
x ax bxa b
y ay bya b
=−−
=−−
2 1 2 1,
a bO x y A x y
A
= =− = =
′ =− −−
3 11 3 0 0
3 0 1 13 1
3 01 1 2 2
,( , ) ( , ); ( , ) ( , )
( ) ( ) , ( ) −−−
= −
= =− = =
1 33 1
12
32
3 11 3 1 41 1
( ) ,
,( , ) ( , ); ( , )a bO x y B (( , )
( ) ( ) , ( ) ( ) ,
,
x y
B
a
2 2
3 1 1 13 1
3 4 1 33 1
2 92
3
′ =− −−
−−
=
= bbO x y C x y
C
=− = =
′ =− −−
−
11 3 4 1
3 4 1 13 1
3 1 11 1 2 2( , ) ( , ); ( , ) ( , )
( ) ( ) , ( ) (333 1
132
0) ,−
=
Question 6 (25 marks)Question 6 (a)
Question 6 (b)
Question 6 (c)
external Division
Sample 4
Paper 2
84 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
sin( ) sin
sin( ) sin
sin sin
∠=
∠ =
∠ = −
CAD
CAD
CAD
4010054
40 10054
40 11
o
o
00054
46 8o
o
= .
AC
AC
2 2 230 40 2 30 40 100
54
= + −
∴ =
( )( ) cos o
cm
sin( )
sin .
sin . .
∠ =
∴ =
= =
CADBD
BD
BD
12
30
46 860
60 46 8 43 7
o
o m
Question 9 (c)
(i)
(ii)
(iii)
(iv) Area cmo= =( )( )sin30 40 100 1182 2
A
C
Question 9 (d)
Draw a line segment [AC] of length 10 cm.Using a compass draw an arc of radius 10 cm with C as centre.Using a set square place a rule perpendicular to AC and move the ruler into position such that it measures a chord of distance of 10 cm. Draw a line along the ruler in this position.
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
− × + =
− + ==
= =
321 5 6
5 27275
5 40
712
512
12x
xx
x .
Question 7 (e)
A probability of 10.2% means that a fair die will give six or more 4s 10.2% of the time in 20 throws of a die. So there is nothing unusual about the die used in the casino. If the probability of at least six 4s when a fair die was tossed 20 times was less that 5% then this probability is so small that it hasn’t happened by chance and so the die is biased.
PP
P C C C
( )( )
{ ( ) ( ) ( ) ( )
44
1
16
56
200
16
0 56
20 201
16
1 56
19 202
=
=
= − + +
Not
(( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )16
2 56
18 203
16
3 56
17 204
16
4 56
16 205
16
5 56+ + +C C C 115
1 0 8980 10210 2
}.
.. %
= −==
Question 8 (25 marks)Question 8 (a)
Question 8 (b)
(i) A rhombus is a simple quadilateral whose sides are equal.(ii) The angles in a quadrilateral add up to 360o. If each angle is equal, each angle will be 90o and hence a square is the shape formed.
Area of Area of Ar
∆ = =
∆ = =
ADC p q pqABC p q pq
12
12
14
12
12
14
( )( )( )( )
eea of ABCD pq pq pq= + =14
14
12
Area of Area of Area of
∆ =
∆ =
=
ADC abABC abABCD ab
1212
sinsin
s
θ
θiinθ
3030
40
p
C
A
BDq
O
40
100o
100o
Question 9 (75 marks)Question 9 (a)
(i) Perimeter P = 2a + 2bQuestion 9 (b)
(ii)
85Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
sin( ) sin
sin( ) sin
sin sin
∠=
∠ =
∠ = −
CAD
CAD
CAD
4010054
40 10054
40 11
o
o
00054
46 8o
o
= .
AC
AC
2 2 230 40 2 30 40 100
54
= + −
∴ =
( )( ) cos o
cm
sin( )
sin .
sin . .
∠ =
∴ =
= =
CADBD
BD
BD
12
30
46 860
60 46 8 43 7
o
o m
Question 9 (c)
(i)
(ii)
(iii)
(iv) Area cmo= =( )( )sin30 40 100 1182 2
A
C
Question 9 (d)
Draw a line segment [AC] of length 10 cm.Using a compass draw an arc of radius 10 cm with C as centre.Using a set square place a rule perpendicular to AC and move the ruler into position such that it measures a chord of distance of 10 cm. Draw a line along the ruler in this position.
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
− × + =
− + ==
= =
321 5 6
5 27275
5 40
712
512
12x
xx
x .
Question 7 (e)
A probability of 10.2% means that a fair die will give six or more 4s 10.2% of the time in 20 throws of a die. So there is nothing unusual about the die used in the casino. If the probability of at least six 4s when a fair die was tossed 20 times was less that 5% then this probability is so small that it hasn’t happened by chance and so the die is biased.
PP
P C C C
( )( )
{ ( ) ( ) ( ) ( )
44
1
16
56
200
16
0 56
20 201
16
1 56
19 202
=
=
= − + +
Not
(( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )16
2 56
18 203
16
3 56
17 204
16
4 56
16 205
16
5 56+ + +C C C 115
1 0 8980 10210 2
}.
.. %
= −==
Question 8 (25 marks)Question 8 (a)
Question 8 (b)
(i) A rhombus is a simple quadilateral whose sides are equal.(ii) The angles in a quadrilateral add up to 360o. If each angle is equal, each angle will be 90o and hence a square is the shape formed.
Area of Area of Ar
∆ = =
∆ = =
ADC p q pqABC p q pq
12
12
14
12
12
14
( )( )( )( )
eea of ABCD pq pq pq= + =14
14
12
Area of Area of Area of
∆ =
∆ =
=
ADC abABC abABCD ab
1212
sinsin
s
θ
θiinθ
3030
40
p
C
A
BDq
O
40
100o
100o
Question 9 (75 marks)Question 9 (a)
(i) Perimeter P = 2a + 2bQuestion 9 (b)
(ii)
Sample 4
Paper 2
86 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
tan tan( )tan tan
tan tan
15 45 3045 30
1 45 30
1 13
1 13
1
o o o
o o
o o
= −
=−
+
=−
+
=−−
+
× =−+
=−+
×−−
=− +
13
1 13
33
3 13 1
3 13 1
3 13 1
3 2 3( )( )
( )( )
113 1
4 2 32
2 3
−
=−
= −
Question 9 (f)
sin sin ( )θ θ= = ⇒ = =−d
d2 1 1
212
30oC
A
BD
d
2
d
2
d
d
E
15o
60o
75o
75o
θ 30o30
o
60o
∠ = ∠ = ∠ = ∠ =ADC ABC BAD BCD75 75 150 60o o o o, , ,
Question 9 (e) (ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
A
C
D B
Draw the kite ABCD.
C
A
BD
d
2
d
2
d
dd
x
h
E
Consider the right-angled triangle BEC:
x d h d d d d= − = − = −
=
−
32
1 32
2 32
d h d
d h d
h d d d
h d d
2 22
2 22
2 22 2
2
2
4
43
43
43
2
= +
= +
∴ = − =
= =
Consider the right-angled triangle BEA:
tan( ) ( )
tan ( )
∠ =
−
= −
∴ ∠ = − =−
ABDd
d
ABD
2 32
2
2 3
2 3 151 o
Question 9 (e) (i)
87Higher Level, Educate.ie Sample 4, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
tan tan( )tan tan
tan tan
15 45 3045 30
1 45 30
1 13
1 13
1
o o o
o o
o o
= −
=−
+
=−
+
=−−
+
× =−+
=−+
×−−
=− +
13
1 13
33
3 13 1
3 13 1
3 13 1
3 2 3( )( )
( )( )
113 1
4 2 32
2 3
−
=−
= −
Question 9 (f)
sin sin ( )θ θ= = ⇒ = =−d
d2 1 1
212
30oC
A
BD
d
2
d
2
d
d
E
15o
60o
75o
75o
θ 30o30
o
60o
∠ = ∠ = ∠ = ∠ =ADC ABC BAD BCD75 75 150 60o o o o, , ,
Question 9 (e) (ii)
LC HigHer LeveL SoLutionS SampLe paper 4 (© Educate.ie)
A
C
D B
Draw the kite ABCD.
C
A
BD
d
2
d
2
d
dd
x
h
E
Consider the right-angled triangle BEC:
x d h d d d d= − = − = −
=
−
32
1 32
2 32
d h d
d h d
h d d d
h d d
2 22
2 22
2 22 2
2
2
4
43
43
43
2
= +
= +
∴ = − =
= =
Consider the right-angled triangle BEA:
tan( ) ( )
tan ( )
∠ =
−
= −
∴ ∠ = − =−
ABDd
d
ABD
2 32
2
2 3
2 3 151 o
Question 9 (e) (i)
Sample 4
Paper 2
88 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
x yx y y x
x xx x xx
2 2
2 2
2 2
2
2 23 7 3 7
2 2 3 72 2 9 42 492 1
− == + ⇒ = −
− = −
− = − +
− =
( )( )88 84 98
0 17 84 1000 17 50 2
22 3 2
2
2
5017
x xx xx x
xx y
− +
= − += − −
∴ =
= =
( )( ),
: ( )): ( )
: ( , ), (
− = − = −= = − = − =
−
7 6 7 13 7 7
2 1
5017
5017
15017
3117
5017
x yAns ,, )31
17
x kx x x x axx kx x x a x a
3 2 2
3 2 3 2
22 56 4 1422 56 4 4
− − + = + + +
− − + = + + + +
( )( )( ) ( 114 56
22 4 14 4 36 94 9 4 5 5
)x
a a ak a k k
+
∴− = + ⇒ = − ⇒ = −∴− = + ⇒ − = − + = − ⇒ =
x x x x x xx x x
x
3 2 25 22 56 4 9 14 04 2 7 0
4 2 7
− − + = + − + =+ − − =
∴ = −
( )( )( )( )( )
, ,
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
[Replace y in the quadratic equation.]
[A cubic is equal to a linear by a quadratic.]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Im
Re
1
2
3
4
0�1�2�3�4
�1
�2
�3
�4
1 2 3 4
z i z=4
iz
i z3
i z2
z i m
iz i i i i i m
i z i i
= + → =
= + = + = − + → = −
= − + = − −
3 4
3 4 3 4 4 3
1 3 4 3 4
43
2 34
2
( )
( ) →→ =
= − + = − − = − → = −
= + = + → =
m
i z i i i i i m
i z i i m
43
3 2 34
4 43
3 4 3 4 4 3
1 3 4 3 4
( )
( )
Multiplying a complex number z by: Causes:i an anti-clockwise rotation of 90o to zi
2 an anti-clockwise rotation of 180o to zi
3 an anti-clockwise rotation of 270o to zi
4 an anti-clockwise rotation of 360o to z
Question 1 (25 marks)Question 1 (a)
sample paper 5: paper 1
Question 1 (b)
Question 1 (c)
89Higher Level, Educate.ie Sample 5, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
x yx y y x
x xx x xx
2 2
2 2
2 2
2
2 23 7 3 7
2 2 3 72 2 9 42 492 1
− == + ⇒ = −
− = −
− = − +
− =
( )( )88 84 98
0 17 84 1000 17 50 2
22 3 2
2
2
5017
x xx xx x
xx y
− +
= − += − −
∴ =
= =
( )( ),
: ( )): ( )
: ( , ), (
− = − = −= = − = − =
−
7 6 7 13 7 7
2 1
5017
5017
15017
3117
5017
x yAns ,, )31
17
x kx x x x axx kx x x a x a
3 2 2
3 2 3 2
22 56 4 1422 56 4 4
− − + = + + +
− − + = + + + +
( )( )( ) ( 114 56
22 4 14 4 36 94 9 4 5 5
)x
a a ak a k k
+
∴− = + ⇒ = − ⇒ = −∴− = + ⇒ − = − + = − ⇒ =
x x x x x xx x x
x
3 2 25 22 56 4 9 14 04 2 7 0
4 2 7
− − + = + − + =+ − − =
∴ = −
( )( )( )( )( )
, ,
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
[Replace y in the quadratic equation.]
[A cubic is equal to a linear by a quadratic.]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Im
Re
1
2
3
4
0�1�2�3�4
�1
�2
�3
�4
1 2 3 4
z i z=4
iz
i z3
i z2
z i m
iz i i i i i m
i z i i
= + → =
= + = + = − + → = −
= − + = − −
3 4
3 4 3 4 4 3
1 3 4 3 4
43
2 34
2
( )
( ) →→ =
= − + = − − = − → = −
= + = + → =
m
i z i i i i i m
i z i i m
43
3 2 34
4 43
3 4 3 4 4 3
1 3 4 3 4
( )
( )
Multiplying a complex number z by: Causes:i an anti-clockwise rotation of 90o to zi
2 an anti-clockwise rotation of 180o to zi
3 an anti-clockwise rotation of 270o to zi
4 an anti-clockwise rotation of 360o to z
Question 1 (25 marks)Question 1 (a)
sample paper 5: paper 1
Question 1 (b)
Question 1 (c)
Sample 5
Paper 1
90 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
S S a rr
b rr
ar
br r
a br
n n
n n
2
2 2
2
11
11
1 1 1
1
1
= ⇒−−
=−−
−=
+ −
=+
+
( ) ( )
( ) ( )( )
( rr ba
r ba
) =
∴ = −1
Question 4 (25 marks)Question 4 (a)
Question 4 (b)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = 7:
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 7 and true for n = k means it is true for n = k + 1. This implies it is true for all n n≥ ∈7, .�
7 50403 2187
7 3
7
7
!
!
=
=
∴ >
3. Prove true for n = k + 1: Prove (k + 1)! > 3k + 1
Proof:
[Therefore, true for n = 7.]
2. Assume true for n = k: Assume k! > 3k
b br brb r
S b rn
n
, , ,..........,
(
2 4
2
21First term Common ratio= =
=− ))
, , ,..........,
(
1 2
2
2
−
= =
=
r
a ar ara r
S an
First term Common ratio111
2−−rr
n )
( )! ( ) !( )
( ) !
k k kk
k k
k
k
k
+ = +
> +
> ×
∴ + > +
1 11 3
3 31 3 1
[From step 2 where k! > 3k][(k + 1) > 3 because k ≥ 7 ⇒ (k + 1) ≥ 8]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
f x b bb b
f a b bb b
b b b bb
x x
x x
a a
a a
a a a a
a
( )
( )
=+−
= ⇒+−
=
+ = −
=
−
−
−
−
− −
−
3 3
3 34 2242
2 2
bbbb
a
a
a
a
=
∴ =
−
f a b bb b
bb
bb
a a
a a
aa
aa
( )2
1
122
53
2 2
2 2
22
22
1212
5232
=+−
=+
−=
+−
= =−
−
log log
log log
log log
(log ) log
(log
b b
b b
b b
b b
b
x x
x x
x x
x x
=
=
=
=
12
12
14
2
xx xx xx x bx x b
b
b
b b
b
b
) loglog (log )
log
log
2
0
4
4 04 0
0 1
4
− =− =
∴ = ⇒ = =
∴ = ⇒ =
44
4
1 171622 0
+ =
== ±
∴ = >
bbb bas
Question 3 (25 marks)Question 3 (a) (i)
Question 3 (a) (ii)
Question 3 (b)
[Square both sides.]
[The roots add to 17.]
91Higher Level, Educate.ie Sample 5, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
S S a rr
b rr
ar
br r
a br
n n
n n
2
2 2
2
11
11
1 1 1
1
1
= ⇒−−
=−−
−=
+ −
=+
+
( ) ( )
( ) ( )( )
( rr ba
r ba
) =
∴ = −1
Question 4 (25 marks)Question 4 (a)
Question 4 (b)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = 7:
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 7 and true for n = k means it is true for n = k + 1. This implies it is true for all n n≥ ∈7, .�
7 50403 2187
7 3
7
7
!
!
=
=
∴ >
3. Prove true for n = k + 1: Prove (k + 1)! > 3k + 1
Proof:
[Therefore, true for n = 7.]
2. Assume true for n = k: Assume k! > 3k
b br brb r
S b rn
n
, , ,..........,
(
2 4
2
21First term Common ratio= =
=− ))
, , ,..........,
(
1 2
2
2
−
= =
=
r
a ar ara r
S an
First term Common ratio111
2−−rr
n )
( )! ( ) !( )
( ) !
k k kk
k k
k
k
k
+ = +
> +
> ×
∴ + > +
1 11 3
3 31 3 1
[From step 2 where k! > 3k][(k + 1) > 3 because k ≥ 7 ⇒ (k + 1) ≥ 8]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
f x b bb b
f a b bb b
b b b bb
x x
x x
a a
a a
a a a a
a
( )
( )
=+−
= ⇒+−
=
+ = −
=
−
−
−
−
− −
−
3 3
3 34 2242
2 2
bbbb
a
a
a
a
=
∴ =
−
f a b bb b
bb
bb
a a
a a
aa
aa
( )2
1
122
53
2 2
2 2
22
22
1212
5232
=+−
=+
−=
+−
= =−
−
log log
log log
log log
(log ) log
(log
b b
b b
b b
b b
b
x x
x x
x x
x x
=
=
=
=
12
12
14
2
xx xx xx x bx x b
b
b
b b
b
b
) loglog (log )
log
log
2
0
4
4 04 0
0 1
4
− =− =
∴ = ⇒ = =
∴ = ⇒ =
44
4
1 171622 0
+ =
== ±
∴ = >
bbb bas
Question 3 (25 marks)Question 3 (a) (i)
Question 3 (a) (ii)
Question 3 (b)
[Square both sides.]
[The roots add to 17.]
Sample 5
Paper 1
92 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
y
y
x=
= = ≈
3
3 3 1 712 .
A
x
1.7
1
0�1�2 21
y
B
2
f x( ) = 3x
x = 12
y xdydx x
= +
=+
ln( )11
1
xx
xx x
++
=+ ++
= ++
31
1 21
1 21
( )( )
xx
dx
xdx
x x
++
= ++
= + += + − +
∫
∫
31
1 21
2 13 2 4 1 2
1
3
1
3
13[ ln( )]
( ln ) ( lln )ln ln(ln ln )ln
23 2 4 1 2 22 2 4 22 2 2
= + − −= + −= +
Average value = +−
= +2 2 2
3 11 2ln ln
The function is not continuous. At x = −1 the function is not defined.
Question 5 (e)
Question 6 (b)
Question 6 (c)
Question 6 (d)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
A
x
2
1
0�1�2 21
y
B
f x af x f a
aa
x( )( , ) ( ) ( )
=
− ∈ ⇒ − = =
= ⇒ =
−1 11 1
33
13
1 13
f xfB
x( )( )
( , )
=
= =∴
30 3 1
0 1
0
The function is not bijective as every y value does not have a corresponding x value. For example, y = − 1
2 has no x value.
A
y x=2
1
0�1�2 21
y
B
f x�1
( )
f x( )
x
y a dydx
a ax x= ⇒ = × ln
y dydx
x x= ⇒ = × >3 3 3 0ln
This is always increasing as ln 3 > 0 and 3x > 0 for all values of x.
Question 5 (b) (i)
Question 5 (b) (ii)
Question 5 (c) [Graph to right]
Question 5 (d)
dydxd ydx
d ydx
x
x
= ×
= ×
=
(ln )
(ln )
3 3
3 32
22
2
2Points of inflection: 00
3 3 03 0
2(ln )( )× =
=
x
x No solutions
There are no points of inflection.
93Higher Level, Educate.ie Sample 5, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)
y
y
x=
= = ≈
3
3 3 1 712 .
A
x
1.7
1
0�1�2 21
y
B
2
f x( ) = 3x
x = 12
y xdydx x
= +
=+
ln( )11
1
xx
xx x
++
=+ ++
= ++
31
1 21
1 21
( )( )
xx
dx
xdx
x x
++
= ++
= + += + − +
∫
∫
31
1 21
2 13 2 4 1 2
1
3
1
3
13[ ln( )]
( ln ) ( lln )ln ln(ln ln )ln
23 2 4 1 2 22 2 4 22 2 2
= + − −= + −= +
Average value = +−
= +2 2 2
3 11 2ln ln
The function is not continuous. At x = −1 the function is not defined.
Question 5 (e)
Question 6 (b)
Question 6 (c)
Question 6 (d)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 5 (25 marks)Question 5 (a)
A
x
2
1
0�1�2 21
y
B
f x af x f a
aa
x( )( , ) ( ) ( )
=
− ∈ ⇒ − = =
= ⇒ =
−1 11 1
33
13
1 13
f xfB
x( )( )
( , )
=
= =∴
30 3 1
0 1
0
The function is not bijective as every y value does not have a corresponding x value. For example, y = − 1
2 has no x value.
A
y x=2
1
0�1�2 21
y
B
f x�1
( )
f x( )
x
y a dydx
a ax x= ⇒ = × ln
y dydx
x x= ⇒ = × >3 3 3 0ln
This is always increasing as ln 3 > 0 and 3x > 0 for all values of x.
Question 5 (b) (i)
Question 5 (b) (ii)
Question 5 (c) [Graph to right]
Question 5 (d)
dydxd ydx
d ydx
x
x
= ×
= ×
=
(ln )
(ln )
3 3
3 32
22
2
2Points of inflection: 00
3 3 03 0
2(ln )( )× =
=
x
x No solutions
There are no points of inflection.
Sample 5
Paper 1
94 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
p ee
=+
≈3000 0 21 0 2
16050 25 7
0 25 7
( . )( . )
. ( )
. ( )
p ee
ee
e
t
t
t
t=+
=+
=
3000 0 21 0 2
6001 0 2
600
0 25
0 25
0 25
0 25
0
( . )( . ) .
.
.
.
.
.225
0 25
0 25
0 25
0 25
0 251 0 2600
0 2
t
t
t
t
t
te
eee
e.
.
.
.
.. .+=
+ −
lim ,n
nr r→∞
= ∞ >1
lim lim.
lim.
.
.
t t t t
t
pe
e→∞ →∞ − →∞
=+
=
+
6000 2
600
0 2 10 25
0 25
=
+∞
=+
=600
0 2 1600
0 2 03000
. .
pe
e
dpdt
e
tt
t
=+
= +
= − +
−− −
− −
6000 2
600 0 2
600 0 2
0 250 25 1
0 25
.( . )
( . )
..
. 22 0 25
0 25 0 25 2
1
0 25
1500 2
1
( ( . ))
( . )
.
. .
e
e edpdt
t
t t
t
−
−
=
× −
=+
=
5500 2
1220 25 0 25 2e e. .( . )+≈− flowers/year
p = 1600 after seven yearsQuestion 7 (d) (i) Question 7 (d) (ii)
Question 7 (e)
Question 7 (f) (i)
Question 7 (f) (ii)
Question 7 (g)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
p keke
t keke
kk
k
t
t=+
= =+
=+
+
30001
0 500 30001
30001
500 1
0 25
0 25
0
0
.
.
:
( ))
.
=+ ==
∴ = =
3000500 500 3000500 2500
5002500
0 2
kk kk
k
p keke
ee
t
t
t
t
=+
=+
30001
1233 3000 0 21 0 2
1233
0 25
0 25
0 25
0 25
.
.
.
.
( . ).
(11 0 2 6001233 246 6 6001233 353
0 25 0 25
0 25 0 25
+ =
+ =
=
. )..
. .
. .
e ee e
t t
t t
441233353 4
1233353 4
0 25
4 12333
0 25
0 25
e
e
t
t
t
t
.
.
.
ln.
.
ln
=
=
∴ =553 4
5.
≈ years
Question 7 (50 marks)Question 7 (a) Question 7 (b)
t (years) 0 2 4 6 8 10p 500 744 1057 1418 1789 2127
1000
4
2000
1500
2500
500
0
p
86 102 t (Years)
1600
Question 7 (c) (i)
Question 7 (c) (ii)
95Higher Level, Educate.ie Sample 5, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
p ee
=+
≈3000 0 21 0 2
16050 25 7
0 25 7
( . )( . )
. ( )
. ( )
p ee
ee
e
t
t
t
t=+
=+
=
3000 0 21 0 2
6001 0 2
600
0 25
0 25
0 25
0 25
0
( . )( . ) .
.
.
.
.
.225
0 25
0 25
0 25
0 25
0 251 0 2600
0 2
t
t
t
t
t
te
eee
e.
.
.
.
.. .+=
+ −
lim ,n
nr r→∞
= ∞ >1
lim lim.
lim.
.
.
t t t t
t
pe
e→∞ →∞ − →∞
=+
=
+
6000 2
600
0 2 10 25
0 25
=
+∞
=+
=600
0 2 1600
0 2 03000
. .
pe
e
dpdt
e
tt
t
=+
= +
= − +
−− −
− −
6000 2
600 0 2
600 0 2
0 250 25 1
0 25
.( . )
( . )
..
. 22 0 25
0 25 0 25 2
1
0 25
1500 2
1
( ( . ))
( . )
.
. .
e
e edpdt
t
t t
t
−
−
=
× −
=+
=
5500 2
1220 25 0 25 2e e. .( . )+≈− flowers/year
p = 1600 after seven yearsQuestion 7 (d) (i) Question 7 (d) (ii)
Question 7 (e)
Question 7 (f) (i)
Question 7 (f) (ii)
Question 7 (g)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
p keke
t keke
kk
k
t
t=+
= =+
=+
+
30001
0 500 30001
30001
500 1
0 25
0 25
0
0
.
.
:
( ))
.
=+ ==
∴ = =
3000500 500 3000500 2500
5002500
0 2
kk kk
k
p keke
ee
t
t
t
t
=+
=+
30001
1233 3000 0 21 0 2
1233
0 25
0 25
0 25
0 25
.
.
.
.
( . ).
(11 0 2 6001233 246 6 6001233 353
0 25 0 25
0 25 0 25
+ =
+ =
=
. )..
. .
. .
e ee e
t t
t t
441233353 4
1233353 4
0 25
4 12333
0 25
0 25
e
e
t
t
t
t
.
.
.
ln.
.
ln
=
=
∴ =553 4
5.
≈ years
Question 7 (50 marks)Question 7 (a) Question 7 (b)
t (years) 0 2 4 6 8 10p 500 744 1057 1418 1789 2127
1000
4
2000
1500
2500
500
0
p
86 102 t (Years)
1600
Question 7 (c) (i)
Question 7 (c) (ii)
Sample 5
Paper 1
96 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
( . ) .. . %
1 055 1 0044717 10 0044717 0 44717
112 = = +
= =i
i
3002 68 6 244 13 72 438 72. . .× − × =
Question 8 (b) (iii)
Question 8 (c) (i)
Question 8 (c) (ii)
Question 8 (c) (iii)
A P i ii
t
t=+
+ −
= ×−
=
( )(( ) )
. ( . )( . )
.
11 1
15 000 0 055 1 0551 055 1
3002 66
6 88
A P i ii
t
t=+
+ −
= ×
( )(( ) )
. ( . )( .
11 1
15 000 0 0044717 1 00447171 004471
72
77 1244 1372 −
=)
.
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
First repayment: A
1 055., Second repayment:
A( . )
,1 055 2 Third repayment:
A( . )1 055 3
Question 8 (a) (ii)
P A A A A A A= + + + + +
1 055 1 055 1 055 1 055 1 055 1 0552 3 4 5 6. ( . ) ( . ) ( . ) ( . ) ( . )
P A A A A A A= + + + + +
1 055 1 055 1 055 1 055 1 055 1 0552 3 4 5 6. ( . ) ( . ) ( . ) ( . ) ( . )
aa A r
S a rr
A
= =
=−−
=−
−
1 0551
1 055
11
1 0551 1
1 055
1 11
6
6 6
.,
.
( ) . .
.0055
15 000 1 0551 1
1 055
1 11 055
15 000 1 11 0556
∴ =−
−⇒
−
A. .
.
.
−
=
∴ =× −
−
1 11 055
1 055
1 055 15 000 1 11 055
1 11
6..
..
.
A
A
0055
3002 68
6
= .
P Ai
Ai
Ai
Ai t
=+
++
++
+ ++( ) ( ) ( )
..................( )1 1 1 11 2 3
P Ai
Ai
Ai
Ai
a A
t=+
++
++
+ ++
=+
( ) ( ) ( )..................
( )
(
1 1 1 1
1
1 2 3
iir
i
S P a rr
Ai i
i
t
t t
),
( )
( ) ( ) ( )
( )
=+
= =−−
=+
−+
−+
=
11
11
11 1
1
1 11
AA ii
i ii
A ii
t
t
t( )( )
( )( )
( )( )
1 11
1 1 11
1 11
+ −+
++ −+
=
+ −+ tt t
t
t
t
iA ii i
A P i ii
=
+ −+
=+
+ −
(( ) )( )
( )(( ) )
1 11
11 1
\
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (iii)
Question 8 (b) (i)
Question 8 (b) (ii)
[This is a geometric series.]
[This is a geometric series.]
97Higher Level, Educate.ie Sample 5, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
( . ) .. . %
1 055 1 0044717 10 0044717 0 44717
112 = = +
= =i
i
3002 68 6 244 13 72 438 72. . .× − × =
Question 8 (b) (iii)
Question 8 (c) (i)
Question 8 (c) (ii)
Question 8 (c) (iii)
A P i ii
t
t=+
+ −
= ×−
=
( )(( ) )
. ( . )( . )
.
11 1
15 000 0 055 1 0551 055 1
3002 66
6 88
A P i ii
t
t=+
+ −
= ×
( )(( ) )
. ( . )( .
11 1
15 000 0 0044717 1 00447171 004471
72
77 1244 1372 −
=)
.
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
First repayment: A
1 055., Second repayment:
A( . )
,1 055 2 Third repayment:
A( . )1 055 3
Question 8 (a) (ii)
P A A A A A A= + + + + +
1 055 1 055 1 055 1 055 1 055 1 0552 3 4 5 6. ( . ) ( . ) ( . ) ( . ) ( . )
P A A A A A A= + + + + +
1 055 1 055 1 055 1 055 1 055 1 0552 3 4 5 6. ( . ) ( . ) ( . ) ( . ) ( . )
aa A r
S a rr
A
= =
=−−
=−
−
1 0551
1 055
11
1 0551 1
1 055
1 11
6
6 6
.,
.
( ) . .
.0055
15 000 1 0551 1
1 055
1 11 055
15 000 1 11 0556
∴ =−
−⇒
−
A. .
.
.
−
=
∴ =× −
−
1 11 055
1 055
1 055 15 000 1 11 055
1 11
6..
..
.
A
A
0055
3002 68
6
= .
P Ai
Ai
Ai
Ai t
=+
++
++
+ ++( ) ( ) ( )
..................( )1 1 1 11 2 3
P Ai
Ai
Ai
Ai
a A
t=+
++
++
+ ++
=+
( ) ( ) ( )..................
( )
(
1 1 1 1
1
1 2 3
iir
i
S P a rr
Ai i
i
t
t t
),
( )
( ) ( ) ( )
( )
=+
= =−−
=+
−+
−+
=
11
11
11 1
1
1 11
AA ii
i ii
A ii
t
t
t( )( )
( )( )
( )( )
1 11
1 1 11
1 11
+ −+
++ −+
=
+ −+ tt t
t
t
t
iA ii i
A P i ii
=
+ −+
=+
+ −
(( ) )( )
( )(( ) )
1 11
11 1
\
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (iii)
Question 8 (b) (i)
Question 8 (b) (ii)
[This is a geometric series.]
[This is a geometric series.]
Sample 5
Paper 1
98 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
AC DC CAC x yDC x y
x xy yC
∩ =− − =+ − =
− = ⇒ =− − = ⇒ = −
∴ −
{ }::
( ,
4 02 5 03 9 0 3
3 4 0 13 11)
E is the midpoint of A and C
A C
E
( , ), ( , )
, ( , )
5 1 3 15 3
21 1
24 0
−
=+ −
=
AC BDA C
AC
BD
⊥−
=− −−
=−−
=
= −
( , ), ( , )5 1 3 11 1
3 522
1Slope of
Slope of 115 3
21 1
24 0
1 4 00 1 4
1 1
E
DB m x yy xy
=+ −
=
= − =− = − −
, ( , )
: , ( , ) ( , )( )
== − ++ − =x
x y4
4 0
DC DB DDC x yDB x y
x xy yD
D
∩ =+ − =
+ − =− = ⇒ =
+ − = ⇒ =∴
{ }::
( , )
2 5 04 01 0 1
1 4 0 31 3
(( , ) ( , ) ( , )1 3 4 0 7 3→ → −E B
BA (5, 1)
D C
E
sample paper 5: paper 2Question 1 (25 marks)Question 1 (a)
Question 1 (b) Question 1 (c)[Diagonals of rhombus are perpendicular.]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 9 (50 marks)
dNdt
et
ÊËÁ
ˆ¯̃
= ==10
0 006 100 8 0 85. .. ( ) billions of barrels per year
Boundary conditions: At t = 0, N = 0.
dNdt
e
dN e dt
N e c e
t
t
t
=
=
= + =
Ú Ú
0 8
0 8
0 80 006
4003
0 006
0 006
0 006 0
.
.
..
.
.
. ..006t c+
N e c
e c c
N e
t
t
= +
\ = + fi = -
= - =
4003
0 4003
4003
4003
4003
4003
0 006
0
0 006
.
. (ee t0 006 1. )-
t N e= = - =20 4003
1 170 006 20: ( ). ( ) billion
N e
e
t
t
t
= - =
= ¥ + =
=
55 4003
1 55
3 55400
1 11380
10 006
11
0 006
0 006
: ( )
.ln
.
.
3380
57 56 58ÊËÁ
ˆ¯̃
= ª. years
dNdt
et
ÊËÁ
ˆ¯̃
= ==20
0 006 200 8 0 90. .. ( ) billions of barrels per year
Question 9 (a) (i)
Question 9 (a) (ii)
Question 9 (b)
Question 9 (c)
1 0 159
4 714 10 4 714 100 159
2 965 1
3
10 310
barrel m
m barrels
=
¥ = ¥
= ¥
.
. ..
. 00296 5 10296 5
11
9
barrelsbarrels
billion barrels= ¥=
.
.
N e
e
t
t
t
= − =
=×
+ =
296 5 4003
1 296 5
3 296 5400
1 2579800
0 006
0 006
. : ( ) .
.
.
.
==
≈
10 006
2579800
195.
ln years
Question 9 (d) Question 9 (e)
99Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
AC DC CAC x yDC x y
x xy yC
∩ =− − =+ − =
− = ⇒ =− − = ⇒ = −
∴ −
{ }::
( ,
4 02 5 03 9 0 3
3 4 0 13 11)
E is the midpoint of A and C
A C
E
( , ), ( , )
, ( , )
5 1 3 15 3
21 1
24 0
−
=+ −
=
AC BDA C
AC
BD
⊥−
=− −−
=−−
=
= −
( , ), ( , )5 1 3 11 1
3 522
1Slope of
Slope of 115 3
21 1
24 0
1 4 00 1 4
1 1
E
DB m x yy xy
=+ −
=
= − =− = − −
, ( , )
: , ( , ) ( , )( )
== − ++ − =x
x y4
4 0
DC DB DDC x yDB x y
x xy yD
D
∩ =+ − =
+ − =− = ⇒ =
+ − = ⇒ =∴
{ }::
( , )
2 5 04 01 0 1
1 4 0 31 3
(( , ) ( , ) ( , )1 3 4 0 7 3→ → −E B
BA (5, 1)
D C
E
sample paper 5: paper 2Question 1 (25 marks)Question 1 (a)
Question 1 (b) Question 1 (c)[Diagonals of rhombus are perpendicular.]
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Question 9 (50 marks)
dNdt
et
ÊËÁ
ˆ¯̃
= ==10
0 006 100 8 0 85. .. ( ) billions of barrels per year
Boundary conditions: At t = 0, N = 0.
dNdt
e
dN e dt
N e c e
t
t
t
=
=
= + =
Ú Ú
0 8
0 8
0 80 006
4003
0 006
0 006
0 006 0
.
.
..
.
.
. ..006t c+
N e c
e c c
N e
t
t
= +
\ = + fi = -
= - =
4003
0 4003
4003
4003
4003
4003
0 006
0
0 006
.
. (ee t0 006 1. )-
t N e= = - =20 4003
1 170 006 20: ( ). ( ) billion
N e
e
t
t
t
= - =
= ¥ + =
=
55 4003
1 55
3 55400
1 11380
10 006
11
0 006
0 006
: ( )
.ln
.
.
3380
57 56 58ÊËÁ
ˆ¯̃
= ª. years
dNdt
et
ÊËÁ
ˆ¯̃
= ==20
0 006 200 8 0 90. .. ( ) billions of barrels per year
Question 9 (a) (i)
Question 9 (a) (ii)
Question 9 (b)
Question 9 (c)
1 0 159
4 714 10 4 714 100 159
2 965 1
3
10 310
barrel m
m barrels
=
¥ = ¥
= ¥
.
. ..
. 00296 5 10296 5
11
9
barrelsbarrels
billion barrels= ¥=
.
.
N e
e
t
t
t
= − =
=×
+ =
296 5 4003
1 296 5
3 296 5400
1 2579800
0 006
0 006
. : ( ) .
.
.
.
==
≈
10 006
2579800
195.
ln years
Question 9 (d) Question 9 (e)
Sample 5
Paper 2
100 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
tantan
6060 3
oo= ⇒ = =
hAC
AC h h
Consider the right-angled triangle DBC.
tantan
3030 1
3
3oo= ⇒ = =
=hDC
DC h h h
Consider the right-angled triangle ADC.
DC AC AD
h h
h h
h
h
2 2 2
22
2
22
2
33
24
33
576
83
576
576 38
= +
=
+
= +
=
∴ =×
( )
==14 7. m
Question 3 (25 marks)Question 3 (a)
Question 3 (b)60
o
h
B
CA
30o
h
B
C
A
24 m
60o
D
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
PO(1, 2)
5
Q(2, 1)�
10
5− k
s x y x y k
O r k k
:
( , ),
2 2
2 2
2 4 0
1 2 1 2 5
+ − − + =
= + − = −Centre
OPQ is a right-angled triangle.
5 5 1025 5 10
20
2 2 2+ − =+ − =
∴ =
( ) ( )kk
k
V( 3, 1)� �
R(0, 0)
U( 2, 6)�
O
r
U V R
RU
( , ), ( , ), ( , )( )
− − −
=− −−
= − = −
2 6 3 1 0 00 2
0 626
13
Slope of
Slope oof RV
RU RV
=− −− −
= =
− × = − ⇒ ⊥
0 30 1
31
3
13
3 1
( )( )
Each angle in a semicircle is a right angle. Therefore [UV] is the diameter of the circle containing points U, V and R.
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
V( 3, 1)� �
W x y( , )
U( 2, 6)�
O
r
Or
Slope of Slope ofUW UVyx
yx
y y x
⊥
∴−+
×++
= −
− − = − +
( )( )
( )( )
(
62
13
1
5 6 52 2 xxx y x y
+
+ + − =
65 5 02 2
)
U V
UV O
( , ), ( , )
,
(
− − −
=− − −
= −
2 6 3 12 32
6 12
Midpoint of Centre
552
52
12
12
2 2
12
12
3 2 1 6
1 49 50
, ) ( , )
( ( )) ( )
=
= = − − − + − −
= + =
h k
r UV
Equatioon of circle : ( ) ( )
( ) ( ) ( )
x h y k r
x y
x x
− + − =
+ + − =
+
2 2 2
52
2 52
2 12
2
2
50
5 ++ + − + =
+ + − =
+
254
2 254
504
2 2
2 2
5
5 5 0
y y
x y x yOr
x yEquation of circle : ++ + + =
∈ + + + + = ⇒ =− − = − ⇒
2 2 00 0 2 2 0 02 2
52
52
gx fy cR x y gx fy c cg f
( , )( , ) ( , ) gg f
x y x y
= = −
∴ + + − =
52
52
2 2 5 5 0
,
101Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
tantan
6060 3
oo= ⇒ = =
hAC
AC h h
Consider the right-angled triangle DBC.
tantan
3030 1
3
3oo= ⇒ = =
=hDC
DC h h h
Consider the right-angled triangle ADC.
DC AC AD
h h
h h
h
h
2 2 2
22
2
22
2
33
24
33
576
83
576
576 38
= +
=
+
= +
=
∴ =×
( )
==14 7. m
Question 3 (25 marks)Question 3 (a)
Question 3 (b)60
o
h
B
CA
30o
h
B
C
A
24 m
60o
D
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
PO(1, 2)
5
Q(2, 1)�
10
5− k
s x y x y k
O r k k
:
( , ),
2 2
2 2
2 4 0
1 2 1 2 5
+ − − + =
= + − = −Centre
OPQ is a right-angled triangle.
5 5 1025 5 10
20
2 2 2+ − =+ − =
∴ =
( ) ( )kk
k
V( 3, 1)� �
R(0, 0)
U( 2, 6)�
O
r
U V R
RU
( , ), ( , ), ( , )( )
− − −
=− −−
= − = −
2 6 3 1 0 00 2
0 626
13
Slope of
Slope oof RV
RU RV
=− −− −
= =
− × = − ⇒ ⊥
0 30 1
31
3
13
3 1
( )( )
Each angle in a semicircle is a right angle. Therefore [UV] is the diameter of the circle containing points U, V and R.
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
V( 3, 1)� �
W x y( , )
U( 2, 6)�
O
r
Or
Slope of Slope ofUW UVyx
yx
y y x
⊥
∴−+
×++
= −
− − = − +
( )( )
( )( )
(
62
13
1
5 6 52 2 xxx y x y
+
+ + − =
65 5 02 2
)
U V
UV O
( , ), ( , )
,
(
− − −
=− − −
= −
2 6 3 12 32
6 12
Midpoint of Centre
552
52
12
12
2 2
12
12
3 2 1 6
1 49 50
, ) ( , )
( ( )) ( )
=
= = − − − + − −
= + =
h k
r UV
Equatioon of circle : ( ) ( )
( ) ( ) ( )
x h y k r
x y
x x
− + − =
+ + − =
+
2 2 2
52
2 52
2 12
2
2
50
5 ++ + − + =
+ + − =
+
254
2 254
504
2 2
2 2
5
5 5 0
y y
x y x yOr
x yEquation of circle : ++ + + =
∈ + + + + = ⇒ =− − = − ⇒
2 2 00 0 2 2 0 02 2
52
52
gx fy cR x y gx fy c cg f
( , )( , ) ( , ) gg f
x y x y
= = −
∴ + + − =
52
52
2 2 5 5 0
,
Sample 5
Paper 2
102 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
σ µµ σµ σ
= =+ = + =− = − =
18 5 55 255 2 18 5 73 755 2 18 5 36 7
. , .. . .. . .
68% of students scored within 1 standard deviation of the mean.
New mean = 58.2New standard deviation = 18.5 (The spread of scores remain unchanged.)
Question 4 (c) (i)
empiriCaL ruLe: In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
Question 4 (c) (ii)
(i) Two events are said to be independent if one event does not affect the outcome of the other.
(ii) If A and B are independent events P A B P A P B( ) ( ) ( )∩ = ×
(iii) If A and B are independent events P(B | A) = P(B)
(iv) For all events P A B P A P B A( ) ( ) ( | )∩ = ×
0.30.2 0.4
A B
P A B P A P B P A B( ) ( ) ( ) ( ). . ..
∪ = + − ∩= + −=
0 7 0 5 0 30 9
P A B P A BP B
( | ) ( )( )
.
.=
∩= =
0 30 7
37
The events are not independent. P A B P A( | ) ( )
.ππ3
7 0 5
Question 5 (25 marks)Question 5 (a)
The events A and B are such that P(A) = 0.5, P(B) = 0.7 and P A B( ) . .∩ = 0 3Question 5 (b)
(i)
(ii)
(iii)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Score f x fx CF
0–10 20 5 100 20
10–20 60 15 900 80
20–30 140 25 3500 220
30–40 200 35 7000 420
40–50 400 45 18 000 820
50–60 500 55 27 500 1320
60–70 430 65 27 950 1750
70–80 260 75 19 500 2010
80–90 140 85 11 900 2150
90–100 60 95 5700 2210
2210 122 050
Number of students = 2210 Mean µ = =122 050
221055 2.
Question 4 (25 marks)Question 4 (a)
Question 4 (a) (i) Question 4 (a) (ii)
Question 4 (b)
The median and mean are nearly the same as the distribution is close to normal.
Num
ber
of
stu
dents
200
100
400
300
600
500
Test Score
10 20 30 40 50 60 70 80 90 1000
The 1105th. student has the median score. This student lies in the 50−60 class interval.
Median =−
× + =( ) .1105 820
50010 50 55 7
103Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
σ µµ σµ σ
= =+ = + =− = − =
18 5 55 255 2 18 5 73 755 2 18 5 36 7
. , .. . .. . .
68% of students scored within 1 standard deviation of the mean.
New mean = 58.2New standard deviation = 18.5 (The spread of scores remain unchanged.)
Question 4 (c) (i)
empiriCaL ruLe: In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
Question 4 (c) (ii)
(i) Two events are said to be independent if one event does not affect the outcome of the other.
(ii) If A and B are independent events P A B P A P B( ) ( ) ( )∩ = ×
(iii) If A and B are independent events P(B | A) = P(B)
(iv) For all events P A B P A P B A( ) ( ) ( | )∩ = ×
0.30.2 0.4
A B
P A B P A P B P A B( ) ( ) ( ) ( ). . ..
∪ = + − ∩= + −=
0 7 0 5 0 30 9
P A B P A BP B
( | ) ( )( )
.
.=
∩= =
0 30 7
37
The events are not independent. P A B P A( | ) ( )
.ππ3
7 0 5
Question 5 (25 marks)Question 5 (a)
The events A and B are such that P(A) = 0.5, P(B) = 0.7 and P A B( ) . .∩ = 0 3Question 5 (b)
(i)
(ii)
(iii)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
Score f x fx CF
0–10 20 5 100 20
10–20 60 15 900 80
20–30 140 25 3500 220
30–40 200 35 7000 420
40–50 400 45 18 000 820
50–60 500 55 27 500 1320
60–70 430 65 27 950 1750
70–80 260 75 19 500 2010
80–90 140 85 11 900 2150
90–100 60 95 5700 2210
2210 122 050
Number of students = 2210 Mean µ = =122 050
221055 2.
Question 4 (25 marks)Question 4 (a)
Question 4 (a) (i) Question 4 (a) (ii)
Question 4 (b)
The median and mean are nearly the same as the distribution is close to normal.
Num
ber
of
stu
dents
200
100
400
300
600
500
Test Score
10 20 30 40 50 60 70 80 90 1000
The 1105th. student has the median score. This student lies in the 50−60 class interval.
Median =−
× + =( ) .1105 820
50010 50 55 7
Sample 5
Paper 2
104 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
No. Maybe there are fewer heavier cars insured with this company or because the premium on these vehicles is so high claims may not be made when minor damage is incurred.
Num
ber
of
cla
ims i
n a
year
10
3000 50004000 600020001000
100
90
80
70
60
40
30
20
Weight of car (kg)
0
50
There is a strong negative correlation between the number of claims per year and the weight of the car.
( , ), ( , )
.
2000 53 5000 1414 53
5000 20000 01m =
−−
= −
Question 7 (e) (i)
Question 7 (e) (ii)
Question 7 (e) (iii)
0 8 0 15 500 0 04 4500 0 01 9500 2000 8 0 15 7. . ( ) . ( ) . ( ). .
M M M MM M+ − + − + − =+ − 55 0 04 180 0 01 95 200
350 200550
+ − + − =− =
∴ =
. .M MM
M
Question 7 (d)
Profit per car () M M – 500 M – 4500 M – 9500Probability 0.8 0.15 0.04 0.01
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
A
B8
E
1.5
4.5
FD C
kEABA
= =+
= =1 5 4 5
1 56
1 54. .
. .
AF
AF
kAFAC AC
AC
2 2 28 6
10
4 10
104
2 5
= +
∴ =
= ⇒ =
∴ = = .
Area of triangle ABC: A = × × =12 1 5 2 1 5. .
Question 6 (25 marks)Question 6 (a)
Question 6 (b)
Question 6 (c)
BC = − =2 5 1 5 22 2. .
12
12
2 2
1 5
2 5 1 53
2 51 2
1 5 1 2 0 9
× =
× × =
∴ = =
= − =
AC BD
BD
BD
AD
.
. .
..
. . .
This is the average payout per claim per year for the company.
P x( ) . . . .> = + + =450 0 15 0 04 0 01 0 2
Question 7 (75 marks)Question 7 (a)Amount of claim x (/year) 0 1000 5000 10 000Probability 0.8 0.15 0.04 0.01
Question 7 (b)
Question 7 (c)
E xP x= = + + + =∑ ( ) ( . ) ( . ) ( . ) ( . )0 0 8 1000 0 15 5000 0 04 10 000 0 01 450
105Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
No. Maybe there are fewer heavier cars insured with this company or because the premium on these vehicles is so high claims may not be made when minor damage is incurred.
Num
ber
of
cla
ims i
n a
year
10
3000 50004000 600020001000
100
90
80
70
60
40
30
20
Weight of car (kg)
0
50
There is a strong negative correlation between the number of claims per year and the weight of the car.
( , ), ( , )
.
2000 53 5000 1414 53
5000 20000 01m =
−−
= −
Question 7 (e) (i)
Question 7 (e) (ii)
Question 7 (e) (iii)
0 8 0 15 500 0 04 4500 0 01 9500 2000 8 0 15 7. . ( ) . ( ) . ( ). .
M M M MM M+ − + − + − =+ − 55 0 04 180 0 01 95 200
350 200550
+ − + − =− =
∴ =
. .M MM
M
Question 7 (d)
Profit per car () M M – 500 M – 4500 M – 9500Probability 0.8 0.15 0.04 0.01
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
A
B8
E
1.5
4.5
FD C
kEABA
= =+
= =1 5 4 5
1 56
1 54. .
. .
AF
AF
kAFAC AC
AC
2 2 28 6
10
4 10
104
2 5
= +
∴ =
= ⇒ =
∴ = = .
Area of triangle ABC: A = × × =12 1 5 2 1 5. .
Question 6 (25 marks)Question 6 (a)
Question 6 (b)
Question 6 (c)
BC = − =2 5 1 5 22 2. .
12
12
2 2
1 5
2 5 1 53
2 51 2
1 5 1 2 0 9
× =
× × =
∴ = =
= − =
AC BD
BD
BD
AD
.
. .
..
. . .
This is the average payout per claim per year for the company.
P x( ) . . . .> = + + =450 0 15 0 04 0 01 0 2
Question 7 (75 marks)Question 7 (a)Amount of claim x (/year) 0 1000 5000 10 000Probability 0.8 0.15 0.04 0.01
Question 7 (b)
Question 7 (c)
E xP x= = + + + =∑ ( ) ( . ) ( . ) ( . ) ( . )0 0 8 1000 0 15 5000 0 04 10 000 0 01 450
Sample 5
Paper 2
106 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
B
7.8 cm
CA 8 cm
5 cm
O
7.8 cm
CA 8 cm
5 cm
B
Tell students to draw the base of the triangle up near the centre of the rectangle in order to leave room below to draw the perpendicular bisectors.
Question 8 (35 marks)Question 8 (a)
Question 8 (b)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
According to this data, the insurance company could claim that its lowest risk is a person aged 69 years driving a car of weight 5800 kg and the highest risk is a person aged 21 years driving a car of weight 1300 kg.
Num
ber
of
cla
ims i
n a
year
10
30 5040 702010
100
90
80
70
60
50
40
30
20
Age in years
0 60
Question 7 (f) (i)
Question 7 (f) (ii)
Outlier (18, 20), learners usually have an experienced driver with them.
Strong negative correlation.
Question 7 (g)
107Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
B
7.8 cm
CA 8 cm
5 cm
O
7.8 cm
CA 8 cm
5 cm
B
Tell students to draw the base of the triangle up near the centre of the rectangle in order to leave room below to draw the perpendicular bisectors.
Question 8 (35 marks)Question 8 (a)
Question 8 (b)
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
According to this data, the insurance company could claim that its lowest risk is a person aged 69 years driving a car of weight 5800 kg and the highest risk is a person aged 21 years driving a car of weight 1300 kg.
Num
ber
of
cla
ims i
n a
year
10
30 5040 702010
100
90
80
70
60
50
40
30
20
Age in years
0 60
Question 7 (f) (i)
Question 7 (f) (ii)
Outlier (18, 20), learners usually have an experienced driver with them.
Strong negative correlation.
Question 7 (g)
Sample 5
Paper 2
108 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
θ
25
7
24
The angle AOC at the centre standing on the arc AC is twice the angle ABC at the circle.
40 2 21600 2 2 21600 2 1 216
2 2 2
2 2
2
= + −
= −
= −
r r r rr rr
( )( ) coscos
( cos )
θ
θ
θ
000 2 1800800 2
400
2 2 2
2 2 2
2 2
= − +
= +
=
=
rr
r
r
( cos sin )(sin sin )
sin
θ θ
θ θ
θ
22224
2520 25
2420 83
∴ =×
=r . km
Question 8 (d)
cos ( cos )
cos cos
2 12
2
1 2
2 2 1
q q
q q
= +
\ = -
40 2 21600 2 2 21600 2 1 216
2 2 2
2 2
2
= + −
= −
= −
r r r rr rr
( )( ) coscos
( cos )
θ
θ
θ
000 2 1 2 11600 4 1
400 1 49625
2 2
2 2
2
= − +
= −
= × −
=
rr
r r
( cos )( cos )
θ
θ
22 576625
400 625576
20 83
∴ =×
=r . km
Alternative method:Apply the Cosine rule to triangle AOC:Apply the Cosine rule to triangle AOC:
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
O
7.8 cm
CA 8 cm
5 cm
B
r
r r
O
39 km
CA 40 km
25 km
B
r
r r
θ
2θ
Let ∠ =
= + −=
∴ =
ABC θ
θθ
θ
40 25 39 2 25 391950 546
54619
2 2 2 ( )( ) coscos
cos550
725
=
Question 8 (c)
109Higher Level, Educate.ie Sample 5, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
θ
25
7
24
The angle AOC at the centre standing on the arc AC is twice the angle ABC at the circle.
40 2 21600 2 2 21600 2 1 216
2 2 2
2 2
2
= + −
= −
= −
r r r rr rr
( )( ) coscos
( cos )
θ
θ
θ
000 2 1800800 2
400
2 2 2
2 2 2
2 2
= − +
= +
=
=
rr
r
r
( cos sin )(sin sin )
sin
θ θ
θ θ
θ
22224
2520 25
2420 83
∴ =×
=r . km
Question 8 (d)
cos ( cos )
cos cos
2 12
2
1 2
2 2 1
q q
q q
= +
\ = -
40 2 21600 2 2 21600 2 1 216
2 2 2
2 2
2
= + −
= −
= −
r r r rr rr
( )( ) coscos
( cos )
θ
θ
θ
000 2 1 2 11600 4 1
400 1 49625
2 2
2 2
2
= − +
= −
= × −
=
rr
r r
( cos )( cos )
θ
θ
22 576625
400 625576
20 83
∴ =×
=r . km
Alternative method:Apply the Cosine rule to triangle AOC:Apply the Cosine rule to triangle AOC:
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
O
7.8 cm
CA 8 cm
5 cm
B
r
r r
O
39 km
CA 40 km
25 km
B
r
r r
θ
2θ
Let ∠ =
= + −=
∴ =
ABC θ
θθ
θ
40 25 39 2 25 391950 546
54619
2 2 2 ( )( ) coscos
cos550
725
=
Question 8 (c)
Sample 5
Paper 2
110 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
4 1 1 1
1 4 1 1 1 0 1 0 011 1
1
T in T i i T
nn n= + − +
= = + − + = + = ⇒ =
[ ( ) ][ ]
: [ ( ) ][ ] [ ][ ]nn T i Tn T= = + − + = − = = ⇒ =
= = +
2 4 1 1 1 2 1 1 2 0 0 03 4 1
22 2
2
3
: [ ( ) ][ ] [ ][ ] [ ][ ]: [ (( ) ][ ] [ ][ ] [ ][ ]
: [ ( ) ][
− + = − − = − = ⇒ =
= = + −
1 1 1 1 1 0 1 0 0
4 4 1 1
3 33
44
i i i Tn T 11 1 1 1 1 2 2 4 1
0 0 0 125 0
44
100
+ = + + = = ⇒ =
∴ = × +
i T
S
] [ ][ ] [ ][ ]
, , , ,........225 0 25 0 25 1 25× + × + × =
Question 1 (25 marks)Question 1 (a)
sample paper 6: paper 1
Question 1 (b)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = − = − =1 7 4 7 4 31 1:
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
3. Prove true for n k b bk k= + − = ∈+ +1 7 4 31 1: ,Prove � Proof:
[Therefore, true for n = 1.]
2. Assume true for n k a a ak k k k= − = ∈ ∴ = +: , . .7 4 3 7 3 4�
7 4 7 7 47 3 4 421 7 4 421 4 7
1 1 1
1
1
k k k k
k k
k k
k
aaa
+ + +
+
+
− = −
= + −
= + × −
= + −
( )( )
( 4421 4 33 7 43
1)( )
( )= +
= +=
aa
b
k
k
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
s1
s2
A
1.5
1.5
1.5
2.75
2.75
h
B
C
D
E
θ
2.75
R
H
BCAB
DEAD h hh h
= ⇒+
=+
+ = ++
1 51 5
2 755 75
1 5 5 75 2 75 1 58 625
..
..
. ( . ) . ( . )
. 11 5 4 125 2 754 5 1 25
4 51 25
3 6
1 51 5 3 6
. . .. .
..
.
sin .. .
h hh
h
= +=
∴ = =
=+
=
cm
θ11 55 1
1 55 1
17 11..
sin ..
.⇒ =
=
−θ o
Height cm
Radius
H
R RH
R
= + + =
= ⇒ =
3 6 2 1 5 2 2 75 12 1
12 1
. ( . ) ( . ) .
: tan . tθ aan . .17 1 3 72o cm=
V R H= = =13
2 13
2 33 72 12 1 175π π ( . ) ( . ) cm
s1
s2
A
1.5
1.5
1.5
2.75
2.75
h
B
C
D
E
θ
2.75
R
H
rr
sin ..
( . ) sin .. sin . sin ..
17 13 6
3 6 17 13 6 17 1 17 13 6
o
o
o o
=−
− =
− =
rr
r rr r
ssin . sin .. sin . ( sin . )
. sin .
17 1 17 13 6 17 1 1 17 1
3 6 17
o o
o o
= +
= +
∴ =
r rr
r 111 17 1
0 82o
o cm( sin . )
.+
=
Volume of empty space with two spheres:V1
43
3 43
3 3175 2 75 1 5 73 75= − − =π π( . ) ( . ) . cm
Volume of empty space with three spheres:V2
43
3 373 75 0 82 71 44= − =. ( . ) .π cm
% . ..
% . %decrease in empty space = −× =
73 75 71 4473 75
100 3 13
Question 9 (40 marks)Question 9 (a)
Question 9 (b)
Question 9 (c)
Question 9 (d)
111Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
4 1 1 1
1 4 1 1 1 0 1 0 011 1
1
T in T i i T
nn n= + − +
= = + − + = + = ⇒ =
[ ( ) ][ ]
: [ ( ) ][ ] [ ][ ]nn T i Tn T= = + − + = − = = ⇒ =
= = +
2 4 1 1 1 2 1 1 2 0 0 03 4 1
22 2
2
3
: [ ( ) ][ ] [ ][ ] [ ][ ]: [ (( ) ][ ] [ ][ ] [ ][ ]
: [ ( ) ][
− + = − − = − = ⇒ =
= = + −
1 1 1 1 1 0 1 0 0
4 4 1 1
3 33
44
i i i Tn T 11 1 1 1 1 2 2 4 1
0 0 0 125 0
44
100
+ = + + = = ⇒ =
∴ = × +
i T
S
] [ ][ ] [ ][ ]
, , , ,........225 0 25 0 25 1 25× + × + × =
Question 1 (25 marks)Question 1 (a)
sample paper 6: paper 1
Question 1 (b)
steps for proof by induction
1. Prove result is true for some starting value of n∈�.2. Assume result is true for n = k.3. Prove result is true for n = (k +1).
1. Prove true for n = − = − =1 7 4 7 4 31 1:
Therefore, assuming true for n = k means it is true for n = k + 1. So true for n = 1 and true for n = k means it is true for n = k + 1. This implies it is true for all n∈�.
3. Prove true for n k b bk k= + − = ∈+ +1 7 4 31 1: ,Prove � Proof:
[Therefore, true for n = 1.]
2. Assume true for n k a a ak k k k= − = ∈ ∴ = +: , . .7 4 3 7 3 4�
7 4 7 7 47 3 4 421 7 4 421 4 7
1 1 1
1
1
k k k k
k k
k k
k
aaa
+ + +
+
+
− = −
= + −
= + × −
= + −
( )( )
( 4421 4 33 7 43
1)( )
( )= +
= +=
aa
b
k
k
LC HigHer LeveL SoLutionS SampLe paper 5 (© Educate.ie)
s1
s2
A
1.5
1.5
1.5
2.75
2.75
h
B
C
D
E
θ
2.75
R
H
BCAB
DEAD h hh h
= ⇒+
=+
+ = ++
1 51 5
2 755 75
1 5 5 75 2 75 1 58 625
..
..
. ( . ) . ( . )
. 11 5 4 125 2 754 5 1 25
4 51 25
3 6
1 51 5 3 6
. . .. .
..
.
sin .. .
h hh
h
= +=
∴ = =
=+
=
cm
θ11 55 1
1 55 1
17 11..
sin ..
.⇒ =
=
−θ o
Height cm
Radius
H
R RH
R
= + + =
= ⇒ =
3 6 2 1 5 2 2 75 12 1
12 1
. ( . ) ( . ) .
: tan . tθ aan . .17 1 3 72o cm=
V R H= = =13
2 13
2 33 72 12 1 175π π ( . ) ( . ) cm
s1
s2
A
1.5
1.5
1.5
2.75
2.75
h
B
C
D
E
θ
2.75
R
H
rr
sin ..
( . ) sin .. sin . sin ..
17 13 6
3 6 17 13 6 17 1 17 13 6
o
o
o o
=−
− =
− =
rr
r rr r
ssin . sin .. sin . ( sin . )
. sin .
17 1 17 13 6 17 1 1 17 1
3 6 17
o o
o o
= +
= +
∴ =
r rr
r 111 17 1
0 82o
o cm( sin . )
.+
=
Volume of empty space with two spheres:V1
43
3 43
3 3175 2 75 1 5 73 75= − − =π π( . ) ( . ) . cm
Volume of empty space with three spheres:V2
43
3 373 75 0 82 71 44= − =. ( . ) .π cm
% . ..
% . %decrease in empty space = −× =
73 75 71 4473 75
100 3 13
Question 9 (40 marks)Question 9 (a)
Question 9 (b)
Question 9 (c)
Question 9 (d)
Sample 6
Paper 1
112 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
T T
TT
n
n
n
n
n
n
n
=
=
=
−
−
−
−
−
2 13
2 13
2 13
2 13
1
1
2
1
1
,
=−n 213
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
3l d�
120o
3l
3 2l d�
( ) ( ) ( ) ( )( ) cos3 3 3 2 2 3 3 2 1209 9 6
2 2 2
2 2 2
l l d l d l d l dl l ld d
= − + − − − −
= − +
o
++ − + − − − +
= − + + − +
9 12 4 2 9 9 2
9 9 6 9 12
2 2 12
2 2
2 2 2 2
l ld d l ld d
l l ld d l ld
( )( )
44 9 9 20 7 27 180 7 6 3
67
3
3 3
2 2 2
2 2
d l ld dd ld ld l d l
d l l
l
+ − +
= − += − −
=
( )( )
,
, ll l l l l l l− − =
67
3 127
3 157
97
, , ,
T S Sn n n= − −1TTn
n−
=1
Constant
a b c bc A2 2 2 2= + − cos
= −
− +
= −
+
=
−
−
3 3 13
3 3 13
3 13
3 13
3 13
1
1
n n
n n
−
=
=
−
− −
n
n n
1
1 1
1 13
3 13
23
2 13
S
S
T S S
n
n
n
n
n n n
= −
= −
= −
−
−
3 1 13
3 1 131
1
−−
−
= −
− −
1
1
3 1 13
3 1 13
n n
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
z i i
z i
=
+
= +
+ = + =
+
cos sinπ π3 3
12
32
1 32
32
32
32
2
= + = =
294
34
124
3
z x iy
x y
x y
= ⇒ + =
∴ + =
+ =
5 5
5
25
2 2
2 2
1
Re
Im
2 3 4 5�1�2�3�4�5
�1
�2
�3
�4
�5
1
2
3
4
5
x = 4
x y2
+ = 252
A B i i∩ = + −{ , }4 3 4 3
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
z zx iy x iyxx
+ =+ + − ==
∴ =
88
2 84
This is a circle with centre (0, 0) and radius 5.
This is a straight line.
113Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
T T
TT
n
n
n
n
n
n
n
=
=
=
−
−
−
−
−
2 13
2 13
2 13
2 13
1
1
2
1
1
,
=−n 213
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
3l d�
120o
3l
3 2l d�
( ) ( ) ( ) ( )( ) cos3 3 3 2 2 3 3 2 1209 9 6
2 2 2
2 2 2
l l d l d l d l dl l ld d
= − + − − − −
= − +
o
++ − + − − − +
= − + + − +
9 12 4 2 9 9 2
9 9 6 9 12
2 2 12
2 2
2 2 2 2
l ld d l ld d
l l ld d l ld
( )( )
44 9 9 20 7 27 180 7 6 3
67
3
3 3
2 2 2
2 2
d l ld dd ld ld l d l
d l l
l
+ − +
= − += − −
=
( )( )
,
, ll l l l l l l− − =
67
3 127
3 157
97
, , ,
T S Sn n n= − −1TTn
n−
=1
Constant
a b c bc A2 2 2 2= + − cos
= −
− +
= −
+
=
−
−
3 3 13
3 3 13
3 13
3 13
3 13
1
1
n n
n n
−
=
=
−
− −
n
n n
1
1 1
1 13
3 13
23
2 13
S
S
T S S
n
n
n
n
n n n
= −
= −
= −
−
−
3 1 13
3 1 131
1
−−
−
= −
− −
1
1
3 1 13
3 1 13
n n
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
z i i
z i
=
+
= +
+ = + =
+
cos sinπ π3 3
12
32
1 32
32
32
32
2
= + = =
294
34
124
3
z x iy
x y
x y
= ⇒ + =
∴ + =
+ =
5 5
5
25
2 2
2 2
1
Re
Im
2 3 4 5�1�2�3�4�5
�1
�2
�3
�4
�5
1
2
3
4
5
x = 4
x y2
+ = 252
A B i i∩ = + −{ , }4 3 4 3
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
z zx iy x iyxx
+ =+ + − ==
∴ =
88
2 84
This is a circle with centre (0, 0) and radius 5.
This is a straight line.
Sample 6
Paper 1
114 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 5 (25 marks)
Question 5 (a)
y f xx
x x x
dydx
xx
= = − +
= − +
= − +
−
−
( ) ln ln2 12
2 12
2 1
2
1
2
× = − +
= ⇒ − + =
− + =∴ =
= = − +
12
2 1
0 2 1 0
2 02
2 22
1 22
2
2
x x
dydx x x
xx
y f ( ) ln = 0
2 0Local minimum A( , )
dydx x x
x x
d ydx
x xx x
d ydx x
= − + = − +
= − = −
= ⇒
− −
− −
2 1 2
4 1 4 1
0 4
22 1
2
23 2
3 2
2
2 3 −− =
− =∴ =
= − +
= − + = −
1 0
4 04
4 24
1 42
1 2 2
2
12
12
xxx
f ( ) ln ln ln
Point oof inflection B( , ln )4 2 12−
dydx x xdydx
t mx
= − +
= − + = − + =
=
2 1
24
14
18
14
18
2
42
Equation of : == −
− + =− + + = ⇒ = −
18
124 2
8 04 8 2 4 0 8 2 8
, ( , ln )
ln ln
Bx y k
k ktEquation of :: (ln )x y− + − =8 8 2 1 0
Question 5 (d)
Question 5 (c)Question 5 (b)
y
x
y f x= ( )
tA
B
dydx x x
xx
dydx
xx
xx x
= − + =−
> ⇒−
>
− >∴ > ∈
2 1 2
0 2 0
2 02
2 2
2
, �
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
x y xy
x y
x yy y
y yy
x
: :
( )
= ⇒ =
∴ =
− =
− =
− =∴ =
= =
3 2 32
32
832
8
3 2 1616
3 162
24
V1 = Volume of small bucketV2 = Volume of large bucket
∴ = ⇒ = =V V V
V1 2 2
1238
86
43
( )( )( )( )( )x a x b x cx a x bx cx bcx bx cx bcx ax abx
+ + +
= + + + +
= + + + + + +
2
3 2 2 2 aacx abcx a b c x ab ac bc abc
+
= + + + + + + +3 2( ) ( )
( )( )( )( ) ( )
x x xx x xx x x
+ + +
= + + + + + + +
= + + +
1 2 31 2 3 2 3 6 66 11 6
3 2
3 2
( )( )( )( ) ( )
x x xx x xx x x
− − +
= + − − + + − − +
= + − +
1 5 71 5 7 5 7 35 35
37 35
3 2
3 2
Question 4 (25 marks)Question 4 (a) Question 4 (b)
Question 4 (c)
Question 4 (c) (i) Question 4 (c) (ii)
115Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 5 (25 marks)
Question 5 (a)
y f xx
x x x
dydx
xx
= = − +
= − +
= − +
−
−
( ) ln ln2 12
2 12
2 1
2
1
2
× = − +
= ⇒ − + =
− + =∴ =
= = − +
12
2 1
0 2 1 0
2 02
2 22
1 22
2
2
x x
dydx x x
xx
y f ( ) ln = 0
2 0Local minimum A( , )
dydx x x
x x
d ydx
x xx x
d ydx x
= − + = − +
= − = −
= ⇒
− −
− −
2 1 2
4 1 4 1
0 4
22 1
2
23 2
3 2
2
2 3 −− =
− =∴ =
= − +
= − + = −
1 0
4 04
4 24
1 42
1 2 2
2
12
12
xxx
f ( ) ln ln ln
Point oof inflection B( , ln )4 2 12−
dydx x xdydx
t mx
= − +
= − + = − + =
=
2 1
24
14
18
14
18
2
42
Equation of : == −
− + =− + + = ⇒ = −
18
124 2
8 04 8 2 4 0 8 2 8
, ( , ln )
ln ln
Bx y k
k ktEquation of :: (ln )x y− + − =8 8 2 1 0
Question 5 (d)
Question 5 (c)Question 5 (b)
y
x
y f x= ( )
tA
B
dydx x x
xx
dydx
xx
xx x
= − + =−
> ⇒−
>
− >∴ > ∈
2 1 2
0 2 0
2 02
2 2
2
, �
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
x y xy
x y
x yy y
y yy
x
: :
( )
= ⇒ =
∴ =
− =
− =
− =∴ =
= =
3 2 32
32
832
8
3 2 1616
3 162
24
V1 = Volume of small bucketV2 = Volume of large bucket
∴ = ⇒ = =V V V
V1 2 2
1238
86
43
( )( )( )( )( )x a x b x cx a x bx cx bcx bx cx bcx ax abx
+ + +
= + + + +
= + + + + + +
2
3 2 2 2 aacx abcx a b c x ab ac bc abc
+
= + + + + + + +3 2( ) ( )
( )( )( )( ) ( )
x x xx x xx x x
+ + +
= + + + + + + +
= + + +
1 2 31 2 3 2 3 6 66 11 6
3 2
3 2
( )( )( )( ) ( )
x x xx x xx x x
− − +
= + − − + + − − +
= + − +
1 5 71 5 7 5 7 35 35
37 35
3 2
3 2
Question 4 (25 marks)Question 4 (a) Question 4 (b)
Question 4 (c)
Question 4 (c) (i) Question 4 (c) (ii)
Sample 6
Paper 1
116 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
t (hours) θ ( )o C 0 37
t 27
t + 1 26
FC F=
= − = − =
71 632 71 6 32 225
959
.( ) ( . )
o
o
FC
k t T TT T T e
a
a akt
= = = =
= + −
= + −
−
−
1 8 0 5 96 22
22 96 22
10
0
. , . , ,
( )
( )
h h C Co o
θ
ee− × ≈1 8 0 5 52. . o C
θ
θ
θ
= + −
− = −
=−−
=
−
−
−
T T T eT T T e
eT T
T
e T
a akt
a akt
kta
a
kt
( )
( )( )( )
(
0
0
0
0
1
−−−
=−−
TT
kt T TT
a
a
a
a
)( )
ln
θ
θ0
Ta = 20oC, T0 = 37oC
kt
k t
=−−
=
+ =−−
ln ln
( ) ln
37 2027 20
177
1 37 2026 20
==
+ − =
−
+ − =
ln
( ) ln ln
ln
176
1 176
177
17
k t kt
kt k kt66
717
76
0 154 1
×
=
=
−k ln . h
Question 7 (50 marks)Question 7 (a)
Question 7 (d) (i)
Question 7 (c)
0 154 177
10 154
177
5 76 5 46
. ln
.ln .
t
t
=
∴ =
= =h h mins
Time of death: 4:44 pm
Question 7 (b)
Question 7 (d) (ii)
Question 7 (d) (iii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)f x x xf x h x h x h
x h x hx h
f x h
( )( ) ( ) ( )
( )
= + −
+ = + + − +
= + + − − −
+
5 45 45 4 4 2
2
2
2 2
−− = + + − − − − − +
= − −
+ −=
−
f x x h x hx h x xh hx h
f x h f xh
h
( )
( ) ( )
5 4 4 2 5 44 2
4
2 2 2
2
22 4 2
4 2
2
0
hx hh
x h
dydx
f x h f xh
xh
−= − −
=+ −
= −
→lim ( ) ( )
y x xx xx xxx
= + −
= − − −
= − − + −
= − − −
= − −
5 44 54 4 92 9
9 2
2
2
2
2
2
( )( )(( ) )
( )Locall maximum: Local maximum: (2, 9)
y x= =9 2,
y x xdydx
x
= + −
= −
5 4
4 2
2
It is not injective because it is not strictly increasing or decreasing for all x∈�. This means that there are y values that correspond to more than one value of x.
Question 6 (b)
Question 6 (d)
Question 6 (c)
117Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
t (hours) θ ( )o C 0 37
t 27
t + 1 26
FC F=
= − = − =
71 632 71 6 32 225
959
.( ) ( . )
o
o
FC
k t T TT T T e
a
a akt
= = = =
= + −
= + −
−
−
1 8 0 5 96 22
22 96 22
10
0
. , . , ,
( )
( )
h h C Co o
θ
ee− × ≈1 8 0 5 52. . o C
θ
θ
θ
= + −
− = −
=−−
=
−
−
−
T T T eT T T e
eT T
T
e T
a akt
a akt
kta
a
kt
( )
( )( )( )
(
0
0
0
0
1
−−−
=−−
TT
kt T TT
a
a
a
a
)( )
ln
θ
θ0
Ta = 20oC, T0 = 37oC
kt
k t
=−−
=
+ =−−
ln ln
( ) ln
37 2027 20
177
1 37 2026 20
==
+ − =
−
+ − =
ln
( ) ln ln
ln
176
1 176
177
17
k t kt
kt k kt66
717
76
0 154 1
×
=
=
−k ln . h
Question 7 (50 marks)Question 7 (a)
Question 7 (d) (i)
Question 7 (c)
0 154 177
10 154
177
5 76 5 46
. ln
.ln .
t
t
=
∴ =
= =h h mins
Time of death: 4:44 pm
Question 7 (b)
Question 7 (d) (ii)
Question 7 (d) (iii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 6 (25 marks)Question 6 (a)f x x xf x h x h x h
x h x hx h
f x h
( )( ) ( ) ( )
( )
= + −
+ = + + − +
= + + − − −
+
5 45 45 4 4 2
2
2
2 2
−− = + + − − − − − +
= − −
+ −=
−
f x x h x hx h x xh hx h
f x h f xh
h
( )
( ) ( )
5 4 4 2 5 44 2
4
2 2 2
2
22 4 2
4 2
2
0
hx hh
x h
dydx
f x h f xh
xh
−= − −
=+ −
= −
→lim ( ) ( )
y x xx xx xxx
= + −
= − − −
= − − + −
= − − −
= − −
5 44 54 4 92 9
9 2
2
2
2
2
2
( )( )(( ) )
( )Locall maximum: Local maximum: (2, 9)
y x= =9 2,
y x xdydx
x
= + −
= −
5 4
4 2
2
It is not injective because it is not strictly increasing or decreasing for all x∈�. This means that there are y values that correspond to more than one value of x.
Question 6 (b)
Question 6 (d)
Question 6 (c)
Sample 6
Paper 1
118 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y (m)
x (m)
80604020 100�40 0�20�100 �60�80
60
80
20
40
200
100
180
140
160
120
h =32 m, y1 = 0 m, y2 = 126 m, y3 = 178 m, y4 = 192 m, y5 = 178 m, y6 = 126 m, y7 = 0 m
A h y y y y y yn n= + + + + + +
= + +
−22
322
0 0 2 1
1 2 3 4 1[ ( ................. )]
[ ( 226 178 192 178 126
25600 2
+ + + +
=
)]
m
e x x
e x x x x
e e x
x
x
x x
= + +
= + − +−
= − +
∴ + = +
−
−
12
12
12
2
2
2 2
2
( ) ( )
Question 8 (c)
Question 8 (d) (i)
e e x
e e x x
y e
x x
x x
+ = +
∴ + = + = +
= −
−
−
2
2 21521
231 19 57
2
139
22
139
139
13
( )
. { 99139
231 19 57 21521
231 39 14 0 013191
2
2
x xe
x
x
+
= − +
= − −
=
− }
.
. ..886 0 013 2− . x
Question 8 (d) (ii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
x (m) –96 –64 –32 0 32 64 96
y (m) 0 126 178 192 178 126 0
y (m)
x (m)
80604020 100�40 0�20�100 �60�80
60
80
20
40
200
100
180
140
160
120
Maximum height = 192 mx = 50 m, y = 154 m
1 0 30481
0 30481
10 3048
192 192 192 629 92126
ft m
ft m
ft m m ft
=
=
× = ⇒ =
.
.
..
%% . % . %error = −
× =
630 629 92126630
100 0 0125
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (ii)
Question 8 (b) (i)
Question 8 (b) (ii)
119Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y (m)
x (m)
80604020 100�40 0�20�100 �60�80
60
80
20
40
200
100
180
140
160
120
h =32 m, y1 = 0 m, y2 = 126 m, y3 = 178 m, y4 = 192 m, y5 = 178 m, y6 = 126 m, y7 = 0 m
A h y y y y y yn n= + + + + + +
= + +
−22
322
0 0 2 1
1 2 3 4 1[ ( ................. )]
[ ( 226 178 192 178 126
25600 2
+ + + +
=
)]
m
e x x
e x x x x
e e x
x
x
x x
= + +
= + − +−
= − +
∴ + = +
−
−
12
12
12
2
2
2 2
2
( ) ( )
Question 8 (c)
Question 8 (d) (i)
e e x
e e x x
y e
x x
x x
+ = +
∴ + = + = +
= −
−
−
2
2 21521
231 19 57
2
139
22
139
139
13
( )
. { 99139
231 19 57 21521
231 39 14 0 013191
2
2
x xe
x
x
+
= − +
= − −
=
− }
.
. ..886 0 013 2− . x
Question 8 (d) (ii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
x (m) –96 –64 –32 0 32 64 96
y (m) 0 126 178 192 178 126 0
y (m)
x (m)
80604020 100�40 0�20�100 �60�80
60
80
20
40
200
100
180
140
160
120
Maximum height = 192 mx = 50 m, y = 154 m
1 0 30481
0 30481
10 3048
192 192 192 629 92126
ft m
ft m
ft m m ft
=
=
× = ⇒ =
.
.
..
%% . % . %error = −
× =
630 629 92126630
100 0 0125
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (ii)
Question 8 (b) (i)
Question 8 (b) (ii) Sample 6
Paper 1
120 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
V t dt
t
=
=−
∫3400 02
100
3400 02
100100
0
0 02
0
0 0
.sin
.cos( )
.
.
p
pp
22
3402
100 0 02 100 0
3402
2 0
= − −
= − −
pp p
pp
(cos( ( . ) cos( ( ))
(cos( cos() ))) = 0
Question 9 (d)
Question 9 (e)
Question 9 (f)
Period sV 2 2200
1100
0 01= = =pp
.
V tdVdt
t t
dVd
=
= × =
340 100
340 100 100 34 000 100
sin( )
cos( ) cos( )
p
p p p p
ttdVdt
t
t
= =
=
−
=
0
1
0 005
34 000 100 0 34 000p p pcos( ( ))
.
Vs
== = =
−
=
34 000 100 0 005 34 000 012
1
0
p p p pcos( ( . )) cos( ) Vs
dVdt t ..
cos( ( . )) cos( )01
134 000 100 0 01 34 000 34 000= = = − −p p p p p Vs
V tV t
t
=
== × −
=
340 100340 100
115 600 1 20057
2 2 2
12
sin( )sin ( )
( cos )
pp
p8800 1 200( cos )− pt
V t dt
t t
2
0
0 0110 01
57 800 1 200
5 780 000 200200
= −
= −
∫.( cos )
sin( )
.p
pp
= −
=
0
0 01
5 780 000 0 01 200 0 01200
5 780 000 0
.
. sin( . ))pp(
.. sin01 2200
57 800 2
−
=
pp
V
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y xy x
x
x
= −
= ⇒ − =
=
=
191 86 0 0130 191 86 0 013 0
191 86 0 013
191 86
2
2
2
. .. .. .
.00 013
243.
≈ m
y ax
y xa
a
a
= −
= = =
=
∴ = =
191 86
0 191 86 96
191 86 9216
191 869216
0 02
2.
: .
.
. . 008
Question 8 (e) Question 8 (f)
Question 9 (50 marks)
t 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04
100pt 0 12 p p 3
2 p 2p 52 p 3p 7
2 p 4p
sin( )100pt 0 1 0 -1 0 1 0 -1 0
340 100sin( )pt 0 340 0 -340 0 340 0 -340 0
V t
P
R
=
= = =
= −
340 1002
1001
500 02
340 340
sin( )
.
[ ,
ppp
Period s s
Range ]]
Maximum voltage is 340 V.
0.01 0.02 0.03 0.04
100
200
300
400
�100
�200
�300
�400
V (V)
t (s)
500
�500
0
Question 9 (a) Question 9 (b)
Question 9 (c)
121Higher Level, Educate.ie Sample 6, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
V t dt
t
=
=−
∫3400 02
100
3400 02
100100
0
0 02
0
0 0
.sin
.cos( )
.
.
p
pp
22
3402
100 0 02 100 0
3402
2 0
= − −
= − −
pp p
pp
(cos( ( . ) cos( ( ))
(cos( cos() ))) = 0
Question 9 (d)
Question 9 (e)
Question 9 (f)
Period sV 2 2200
1100
0 01= = =pp
.
V tdVdt
t t
dVd
=
= × =
340 100
340 100 100 34 000 100
sin( )
cos( ) cos( )
p
p p p p
ttdVdt
t
t
= =
=
−
=
0
1
0 005
34 000 100 0 34 000p p pcos( ( ))
.
Vs
== = =
−
=
34 000 100 0 005 34 000 012
1
0
p p p pcos( ( . )) cos( ) Vs
dVdt t ..
cos( ( . )) cos( )01
134 000 100 0 01 34 000 34 000= = = − −p p p p p Vs
V tV t
t
=
== × −
=
340 100340 100
115 600 1 20057
2 2 2
12
sin( )sin ( )
( cos )
pp
p8800 1 200( cos )− pt
V t dt
t t
2
0
0 0110 01
57 800 1 200
5 780 000 200200
= −
= −
∫.( cos )
sin( )
.p
pp
= −
=
0
0 01
5 780 000 0 01 200 0 01200
5 780 000 0
.
. sin( . ))pp(
.. sin01 2200
57 800 2
−
=
pp
V
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y xy x
x
x
= −
= ⇒ − =
=
=
191 86 0 0130 191 86 0 013 0
191 86 0 013
191 86
2
2
2
. .. .. .
.00 013
243.
≈ m
y ax
y xa
a
a
= −
= = =
=
∴ = =
191 86
0 191 86 96
191 86 9216
191 869216
0 02
2.
: .
.
. . 008
Question 8 (e) Question 8 (f)
Question 9 (50 marks)
t 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04
100pt 0 12 p p 3
2 p 2p 52 p 3p 7
2 p 4p
sin( )100pt 0 1 0 -1 0 1 0 -1 0
340 100sin( )pt 0 340 0 -340 0 340 0 -340 0
V t
P
R
=
= = =
= −
340 1002
100150
0 02
340 340
sin( )
.
[ ,
ppp
Period s s
Range ]]
Maximum voltage is 340 V.
0.01 0.02 0.03 0.04
100
200
300
400
�100
�200
�300
�400
V (V)
t (s)
500
�500
0
Question 9 (a) Question 9 (b)
Question 9 (c)
Sample 6
Paper 1
122 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
3 + 4 + 1 = 0x y
O( 1, 4)�
10
3 + 4 + = 0x y k
r = 5r = 5
43
+=
0x
yk
�
The length of a side of the square is 10 units. A line parallel to 3x + 4y + 1 = 0 has the form 3x + 4y + k = 0.Pick a point on the line 3x + 4y + 1 = 0. (1, -1) is on this line.
d = 10, (x1, y1) = (1, -1)
103 1 4 1
3 4
103 4
550 1
50 149 51
2 2=
+ − +
+
=− +
= −
± = −∴ = −
( ) ( )
,
k
k
kk
k
Equations: 3x + 4y - 49 = 0, 3x + 4y + 51 = 0
3 + 4 + 1 = 0x y
43
+=
0x
yk
�
O( 1, 4)�
r = 5
s x y x y
O r
:
( , ), ( )
2 2
2 2
2 8 8 0
1 4 1 4 8 25 5
+ + − − =
− = − + + = =Centre
Equation of tangents: 4x - 3y + k = 0
dax by c
a b=
+ +
+1 1
2 2
4 1 3 4
4 35
4 1225
5
16 2516 25
9 41
2 2
( ) ( )
( )
,
− − +
+ −=
− − +=
− + =
− + = ±∴ = −
k
k
kk
k
t1: 4x – 3y + 41 = 0, t2: 4x – 3y – 9 = 0
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
dax by c
a b=
+ +
+1 1
2 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
(x, 0) is a point on the x-axis.
dax by c
a b=
+ +
+1 1
2 2Distance d1 of (x, 0) to line k: d
x x1 2 2
3 4 0 5
3 4
3 55
=− +
+=
+( )
Distance d2 of (x, 0) to line l: dx x
2 2 2
5 12 0 1
5 12
5 113
=− −
+=
−( )
d dx x
x xx x xx
1 2
3 55
5 113
13 3 5 5 5 139 65 25 5 14 70
= ⇒+
=−
+ = ± −+ = − ⇒ = −
∴ =
( ) ( )
−−
+ = − + ⇒ = −∴ = −
5
39 65 25 5 64 601516
orx x xx
m2 2= −
m t1 10=
m = − 34
tanθ = −+
m mm m
1 2
1 21
tan ( )( )
tan ( )( )(
θ
θ
=− −
+ −=
+−
=− − −+ − −
t
t
tt
1034
1034
34
34
14 3040 3
21 2 ))
( ) ( )
=− ++
=−
=
∴+−
= ±
+ = −+ =
8 34 6
510
12
4 3040 3
12
2 4 30 1 40 38 60 40
tt
t tt −−= − ⇒ = −
+ = − −+ = − += −
311 20
2 4 30 1 40 38 60 40 35 100
2011
tt t
ort t
t tt
( ) ( )
⇒⇒ = −t 20
Question 1 (25 marks)Question 1 (a)
sample paper 6: paper 2
θθ
Question 1 (b)
anSwerS: ( , ), ( , )- -5 0 01516
123Higher Level, Educate.ie Sample 6, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
3 + 4 + 1 = 0x y
O( 1, 4)�
10
3 + 4 + = 0x y k
r = 5r = 5
43
+=
0x
yk
�
The length of a side of the square is 10 units. A line parallel to 3x + 4y + 1 = 0 has the form 3x + 4y + k = 0.Pick a point on the line 3x + 4y + 1 = 0. (1, -1) is on this line.
d = 10, (x1, y1) = (1, -1)
103 1 4 1
3 4
103 4
550 1
50 149 51
2 2=
+ − +
+
=− +
= −
± = −∴ = −
( ) ( )
,
k
k
kk
k
Equations: 3x + 4y - 49 = 0, 3x + 4y + 51 = 0
3 + 4 + 1 = 0x y
43
+=
0x
yk
�
O( 1, 4)�
r = 5
s x y x y
O r
:
( , ), ( )
2 2
2 2
2 8 8 0
1 4 1 4 8 25 5
+ + − − =
− = − + + = =Centre
Equation of tangents: 4x - 3y + k = 0
dax by c
a b=
+ +
+1 1
2 2
4 1 3 4
4 35
4 1225
5
16 2516 25
9 41
2 2
( ) ( )
( )
,
− − +
+ −=
− − +=
− + =
− + = ±∴ = −
k
k
kk
k
t1: 4x – 3y + 41 = 0, t2: 4x – 3y – 9 = 0
Question 2 (25 marks)Question 2 (a)
Question 2 (b)
dax by c
a b=
+ +
+1 1
2 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
(x, 0) is a point on the x-axis.
dax by c
a b=
+ +
+1 1
2 2Distance d1 of (x, 0) to line k: d
x x1 2 2
3 4 0 5
3 4
3 55
=− +
+=
+( )
Distance d2 of (x, 0) to line l: dx x
2 2 2
5 12 0 1
5 12
5 113
=− −
+=
−( )
d dx x
x xx x xx
1 2
3 55
5 113
13 3 5 5 5 139 65 25 5 14 70
= ⇒+
=−
+ = ± −+ = − ⇒ = −
∴ =
( ) ( )
−−
+ = − + ⇒ = −∴ = −
5
39 65 25 5 64 601516
orx x xx
m2 2= −
m t1 10=
m = − 34
tanθ = −+
m mm m
1 2
1 21
tan ( )( )
tan ( )( )(
θ
θ
=− −
+ −=
+−
=− − −+ − −
t
t
tt
1034
1034
34
34
14 3040 3
21 2 ))
( ) ( )
=− ++
=−
=
∴+−
= ±
+ = −+ =
8 34 6
510
12
4 3040 3
12
2 4 30 1 40 38 60 40
tt
t tt −−= − ⇒ = −
+ = − −+ = − += −
311 20
2 4 30 1 40 38 60 40 35 100
2011
tt t
ort t
t tt
( ) ( )
⇒⇒ = −t 20
Question 1 (25 marks)Question 1 (a)
sample paper 6: paper 2
θθ
Question 1 (b)
anSwerS: ( , ), ( , )- -5 0 01516
Sample 6
Paper 2
124 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
68%
µ�σ��σ µ
�σ��σ µ�σ��σ
97.5%95%
µ σµ σµ µ
σσ
σ
− =+ =
= ⇒ =
− ==
∴ =
2 24 82 36 4
2 61 2 30 6
30 6 2 24 85 8 2
.
.
. .
. ..
years
22 9. years
µσ
µσ
==≥ =
= =−
=−
= −
30 62 9
30
30 30 30 62 9
0 21
..
( ) ?
: ..
.
yearsyears
P x
x z x
PP x P zP zP zP z
( ) ( . )( . )( . )
{ ( .
≥ = ≥ −= − ≤ −= − ≥= − − ≤
30 0 211 0 211 0 211 1 0 21))}
( . )}.. %
= ≤==
P z 0 210 583258 32
Question 4 (25 marks)Question 4 (a)
Question 4 (b) Question 4 (c)
In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
a b c bc A2 2 2 2= + − cos ,
b a c ac B2 2 2 2= + − cos ,
c a b ab C2 2 2 2= + − cos
A
B C
a
bc
|BD| = |DC|A
B CD
7
3.5
4
x x���� � �
� θθ
Apply the Cosine rule to triangle ABD: 4 3 5 2 3 52 2 2= + −. ( . )( ) cosx x θ
Apply the Cosine rule to triangle ADC: 7 3 5 2 3 5 1802 2 2= + − −. ( . )( ) cos( )x x o θ
16 3 5 749 3 5 765 2 3 5 2
2 2
2 2
2 2
2 814
9
= + −
= + +
= +
= ⇒ =
. cos. cos( . )
x xx x
xx x
θ
θ
22
9∴ =BC
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
Question 3 (c)
125Higher Level, Educate.ie Sample 6, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
68%
µ�σ��σ µ
�σ��σ µ�σ��σ
97.5%95%
µ σµ σµ µ
σσ
σ
− =+ =
= ⇒ =
− ==
∴ =
2 24 82 36 4
2 61 2 30 6
30 6 2 24 85 8 2
.
.
. .
. ..
years
22 9. years
µσ
µσ
==≥ =
= =−
=−
= −
30 62 9
30
30 30 30 62 9
0 21
..
( ) ?
: ..
.
yearsyears
P x
x z x
PP x P zP zP zP z
( ) ( . )( . )( . )
{ ( .
≥ = ≥ −= − ≤ −= − ≥= − − ≤
30 0 211 0 211 0 211 1 0 21))}
( . )}.. %
= ≤==
P z 0 210 583258 32
Question 4 (25 marks)Question 4 (a)
Question 4 (b) Question 4 (c)
In any normal distribution with mean x and standard deviation s.1. 68% of the data falls within 1s of the mean x.2. 95% of the data falls within 2s of the mean x.3. 99.7% of the data falls within 3s of the mean x.
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
a b c bc A2 2 2 2= + − cos ,
b a c ac B2 2 2 2= + − cos ,
c a b ab C2 2 2 2= + − cos
A
B C
a
bc
|BD| = |DC|A
B CD
7
3.5
4
x x���� � �
� θθ
Apply the Cosine rule to triangle ABD: 4 3 5 2 3 52 2 2= + −. ( . )( ) cosx x θ
Apply the Cosine rule to triangle ADC: 7 3 5 2 3 5 1802 2 2= + − −. ( . )( ) cos( )x x o θ
16 3 5 749 3 5 765 2 3 5 2
2 2
2 2
2 2
2 814
9
= + −
= + +
= +
= ⇒ =
. cos. cos( . )
x xx x
xx x
θ
θ
22
9∴ =BC
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
Question 3 (c)
Sample 6
Paper 2
126 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
s
B
AC
D
E
β
90o
90
o
�
β
90o
β
90 o
�
β
90 o
�
�β
β
Consider triangle ADE. Let ∠ =DAE β .[AE] is a diameter. Therefore, ∠ =ADE 90o. (The angle at the circle standing on a diameter is a right angle).
∴∠ = − − = −DEA 180 90 90o o oβ β
∠ + ∠ =AED ABD 180o (Opposite angles of a cyclic quadrilateral add up to 180o.)
∴∠ = − − = +ABD 180 90 90o o o( )β β
∠ = ∠ =DAE ADB β (Alternate angles)
∴∠ = − − + = −DAB 180 90 90 2o o oβ β β( )
∴∠ = − − − =BAC 90 90 2o oβ β β( )
∴∠ = ∠ = ∠ =BAC DAE ADB β
Question 6 (25 marks)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y(T
housands)
1 2
3.8
4 5
1
2
3
4
5
6
7
8
9
10
x (cm)
( , )x y
3
4.35
x
y
=+ + + + + + + +
=
=+ + +
4 4 3 0 5 2 5 0 2 1 0 0 1 1 3 29
2 7
5100 7900 900 4000
. . . . . . . .
++ + + + +=
4700 7300 9500 8700 26009
5633
( . , ), ( , )
.
2 7 5633 0 90009000 5633
0 2 71247m =
−−
= −
For every increase of 1 cm in rainfall, there is a decrease in 1247 tourists.
m x yy x
x y
= − =− = − −
+ − =
1247 0 90009000 1247 0
1247 9000 0
1 1, ( , ) ( , )( )
(i) Number of tourists = 4350
x yy= + − =
∴ =3 8 1247 3 8 9000 0
4261. : ( . )
Question 5 (25 marks)Question 5 (a)
Rainfall (x cm) 4.4 3.0 5.2 5.0 2.1 0 0 1.1 3.2Number of tourists (y thousands) 5.1 7.9 0.9 4.0 4.7 7.3 9.5 8.7 2.6
Question 5 (b)
Question 5 (c) [See graph]
Question 5 (d) Question 5 (e)
Question 5 (f) Question 5 (g)
(ii)
The student’s result is smaller by 89 or is about 2% smaller ( % %).89
4350 100 2× ≈
127Higher Level, Educate.ie Sample 6, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
s
B
AC
D
E
β
90o
90
o
�
β
90o
β
90 o
�
β
90 o
�
�β
β
Consider triangle ADE. Let ∠ =DAE β .[AE] is a diameter. Therefore, ∠ =ADE 90o. (The angle at the circle standing on a diameter is a right angle).
∴∠ = − − = −DEA 180 90 90o o oβ β
∠ + ∠ =AED ABD 180o (Opposite angles of a cyclic quadrilateral add up to 180o.)
∴∠ = − − = +ABD 180 90 90o o o( )β β
∠ = ∠ =DAE ADB β (Alternate angles)
∴∠ = − − + = −DAB 180 90 90 2o o oβ β β( )
∴∠ = − − − =BAC 90 90 2o oβ β β( )
∴∠ = ∠ = ∠ =BAC DAE ADB β
Question 6 (25 marks)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
y(T
housands)
1 2
3.8
4 5
1
2
3
4
5
6
7
8
9
10
x (cm)
( , )x y
3
4.35
x
y
=+ + + + + + + +
=
=+ + +
4 4 3 0 5 2 5 0 2 1 0 0 1 1 3 29
2 7
5100 7900 900 4000
. . . . . . . .
++ + + + +=
4700 7300 9500 8700 26009
5633
( . , ), ( , )
.
2 7 5633 0 90009000 5633
0 2 71247m =
−−
= −
For every increase of 1 cm in rainfall, there is a decrease in 1247 tourists.
m x yy x
x y
= − =− = − −
+ − =
1247 0 90009000 1247 0
1247 9000 0
1 1, ( , ) ( , )( )
(i) Number of tourists = 4350
x yy= + − =
∴ =3 8 1247 3 8 9000 0
4261. : ( . )
Question 5 (25 marks)Question 5 (a)
Rainfall (x cm) 4.4 3.0 5.2 5.0 2.1 0 0 1.1 3.2Number of tourists (y thousands) 5.1 7.9 0.9 4.0 4.7 7.3 9.5 8.7 2.6
Question 5 (b)
Question 5 (c) [See graph]
Question 5 (d) Question 5 (e)
Question 5 (f) Question 5 (g)
(ii)
The student’s result is smaller by 89 or is about 2% smaller ( % %).89
4350 100 2× ≈
Sample 6
Paper 2
128 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
6 1 18 1 38 38 1 18 1 18 1 2 124 38 38 38 3876 52
× + × + = − + × + × + ×+ = − +=
=
x xx x
x
x
( )
55276
1319
77 5 4 80 21319
=
∴ = + × =Median . .
Mean Median
difference
µ ==
=−
× =
81 280 2
81 2 80 281 2
100 1 23
..
% . ..
% . %
(ii) It is approximately normal because the mean is approximately equal to the median.
σ = 4 75.
Question 7 (c)
µ σ
µσ
= =≤ = ⇒ =
=−
⇒ =−
∴ =
81 2 4 750 9 1 28
1 28 81 24 75
87
. , .( ) . .
. ..
.
P z Z z
z x x
x 33%
µ σ
µσ
= =< =
= =−
=−
=
< =
81 2 4 7585
85 85 81 24 75
0 8
0 8
. , .( ) ?
: ..
.
( . )
P x
x z x
P z 00 7881 78 8. . %=
(iii)
(i)
Question 7 (d)(i) (ii)
Conditions for a Bernoulli Trial:Condition: There are only two possible outcomes (success or failure) in each trial.Condition: There is a fixed number of trials n.Condition: The probability of success p is fixed from trial to trial.Condition: The trials are independent.Condition: The binomial random variable is the number of successes in n trials.
(iii) He has two successes and two failures on the first four throws and he scores on the last.
Question 7 (e)
Question 7 (f)(i)
(ii)
PPP C
( ) .( ) .( ) ( .
SuccessFailureScores all five
==
=
0 9270 073
0 955 227 0 073 0 685 68 55 0) ( . ) . . %= =
P C( ) ( . ) ( . ) . . %Scores three out of five = = =53
3 20 927 0 073 0 042 4 2
P C( ) ( . )Scores two out of first four and scores last = 42 0 927 22 20 073 0 927 0 025 2 5( . ) ( . ) . . %= =
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Percentage success Frequency f Mid-interval Value x fx
70–74 6 72 432
74–78 18 76 1368
78–82 38 80 3040
82–86 18 84 1512
86–90 18 88 1584
90–94 2 92 184
100 8120
µ = = =∑∑fxf
8120100
81 2.
Mean percentage success rate = 81.2%
Question 7 (50 marks)Question 7 (a)
40
35
30
25
20
15
10
94
5
86 9078 8270 74
Num
ber
of
pla
yers
Percentage success rate at the free-throw line
Percentage success Cumulative frequency< 74 6< 78 24< 82 62< 86 80< 90 98< 94 100
Median
Question 7 (b)
129Higher Level, Educate.ie Sample 6, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
6 1 18 1 38 38 1 18 1 18 1 2 124 38 38 38 3876 52
× + × + = − + × + × + ×+ = − +=
=
x xx x
x
x
( )
55276
1319
77 5 4 80 21319
=
∴ = + × =Median . .
Mean Median
difference
µ ==
=−
× =
81 280 2
81 2 80 281 2
100 1 23
..
% . ..
% . %
(ii) It is approximately normal because the mean is approximately equal to the median.
σ = 4 75.
Question 7 (c)
µ σ
µσ
= =≤ = ⇒ =
=−
⇒ =−
∴ =
81 2 4 750 9 1 28
1 28 81 24 75
87
. , .( ) . .
. ..
.
P z Z z
z x x
x 33%
µ σ
µσ
= =< =
= =−
=−
=
< =
81 2 4 7585
85 85 81 24 75
0 8
0 8
. , .( ) ?
: ..
.
( . )
P x
x z x
P z 00 7881 78 8. . %=
(iii)
(i)
Question 7 (d)(i) (ii)
Conditions for a Bernoulli Trial:Condition: There are only two possible outcomes (success or failure) in each trial.Condition: There is a fixed number of trials n.Condition: The probability of success p is fixed from trial to trial.Condition: The trials are independent.Condition: The binomial random variable is the number of successes in n trials.
(iii) He has two successes and two failures on the first four throws and he scores on the last.
Question 7 (e)
Question 7 (f)(i)
(ii)
PPP C
( ) .( ) .( ) ( .
SuccessFailureScores all five
==
=
0 9270 073
0 955 227 0 073 0 685 68 55 0) ( . ) . . %= =
P C( ) ( . ) ( . ) . . %Scores three out of five = = =53
3 20 927 0 073 0 042 4 2
P C( ) ( . )Scores two out of first four and scores last = 42 0 927 22 20 073 0 927 0 025 2 5( . ) ( . ) . . %= =
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Percentage success Frequency f Mid-interval Value x fx
70–74 6 72 432
74–78 18 76 1368
78–82 38 80 3040
82–86 18 84 1512
86–90 18 88 1584
90–94 2 92 184
100 8120
µ = = =∑∑fxf
8120100
81 2.
Mean percentage success rate = 81.2%
Question 7 (50 marks)Question 7 (a)
40
35
30
25
20
15
10
94
5
86 9078 8270 74
Num
ber
of
pla
yers
Percentage success rate at the free-throw line
Percentage success Cumulative frequency< 74 6< 78 24< 82 62< 86 80< 90 98< 94 100
Median
Question 7 (b)
Sample 6
Paper 2
130 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
OC
OC OD DF FE ECa b
a b
=
= + + +
∴ = + + ++ =
10
10 3 52
cm
A
B
a
C
O
D
E
5
b
F
5
33
*
*
(ii) Triangles OAF and CBF are similar because:
∠ = ∠
∠ = ∠
∴ ∠ = ∠
OAF FBC
OFA BFC
AOF B
( )
( )
90o angles
Vertically opposite
CCF
BCOA
FCOF
ba
a ba b
b a
a b
a a a
= ⇒ =++
+ = +=
∴ =
+ =
+ = ⇒ +
53
53
5 15 3 155 3
532
53
2 3 5aa
aa
b
=
=∴ =
∴ = =
6
8 60 755 0 75
31 25
.( . ) .
cm
cm
AB AF FB
AOF OF OA AF
AF
AF
FB
= +
∆ = +
∴ = +
= − =
∆
:
.
. .
2 2 2
2 2 2
2 2
3 75 3
3 75 3 2 25 cm
CC FC BC FB
FB
FB
AB
:
.
. .
. .
2 2 2
2 2 2
2 2
6 25 5
6 25 5 3 75
2 25 3 75
= +
∴ = +
= − =
∴ = +
cm
== 6 cm
Question 9 (70 marks)Question 9 (a)(i)
(iii)
(iv)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 8 (30 marks)Question 8 (a)
True population proportion = Sample proportion ± 1.96(Standard error of the proportion)
Standard error of the proportion = -p pn
( )1
Confidence interval = [sample parameter - 1.96(standard error), sample parameter + 1.96(standard error)]
For about 95% of all samples the confidence interval covers the population values of the parameter and for the other 5% it does not.For a 99% confidence level, the confidence interval must be wider so that more samples cover the population parameter.
Confidence interval = [sample parameter - 2.576(standard error), sample parameter + 2.576(standard error)]
Sample proportion
Population proportion
p
n
= =
=
=
200300
23
300
23
±± - =1 96 1300
0 613 0 7223
23. ( ) . , .
Confidence interval = [0.613, 0.72]For about 95% of all samples, the population proportion of all fifth years who believe the Junior Certificate should be scrapped is between 61.3% and 72%.
m s= ± ¥xn
1 96.Standard deviation of population s = 10 cmMean of the sample x = 173 cmNumber of the sample n = 50Population mean m = ?
m = ± ¥ =173 170 23 175 771.96 1050
. , .
For about 95% of all samples, the population mean height of university students is between 170.23 cm and 175.77 cm.
Question 8 (b)
Question 8 (c)
131Higher Level, Educate.ie Sample 6, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
OC
OC OD DF FE ECa b
a b
=
= + + +
∴ = + + ++ =
10
10 3 52
cm
A
B
a
C
O
D
E
5
b
F
5
33
*
*
(ii) Triangles OAF and CBF are similar because:
∠ = ∠
∠ = ∠
∴ ∠ = ∠
OAF FBC
OFA BFC
AOF B
( )
( )
90o angles
Vertically opposite
CCF
BCOA
FCOF
ba
a ba b
b a
a b
a a a
= ⇒ =++
+ = +=
∴ =
+ =
+ = ⇒ +
53
53
5 15 3 155 3
532
53
2 3 5aa
aa
b
=
=∴ =
∴ = =
6
8 60 755 0 75
31 25
.( . ) .
cm
cm
AB AF FB
AOF OF OA AF
AF
AF
FB
= +
∆ = +
∴ = +
= − =
∆
:
.
. .
2 2 2
2 2 2
2 2
3 75 3
3 75 3 2 25 cm
CC FC BC FB
FB
FB
AB
:
.
. .
. .
2 2 2
2 2 2
2 2
6 25 5
6 25 5 3 75
2 25 3 75
= +
∴ = +
= − =
∴ = +
cm
== 6 cm
Question 9 (70 marks)Question 9 (a)(i)
(iii)
(iv)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
Question 8 (30 marks)Question 8 (a)
True population proportion = Sample proportion ± 1.96(Standard error of the proportion)
Standard error of the proportion = -p pn
( )1
Confidence interval = [sample parameter - 1.96(standard error), sample parameter + 1.96(standard error)]
For about 95% of all samples the confidence interval covers the population values of the parameter and for the other 5% it does not.For a 99% confidence level, the confidence interval must be wider so that more samples cover the population parameter.
Confidence interval = [sample parameter - 2.576(standard error), sample parameter + 2.576(standard error)]
Sample proportion
Population proportion
p
n
= =
=
=
200300
23
300
23
±± - =1 96 1300
0 613 0 7223
23. ( ) . , .
Confidence interval = [0.613, 0.72]For about 95% of all samples, the population proportion of all fifth years who believe the Junior Certificate should be scrapped is between 61.3% and 72%.
m s= ± ¥xn
1 96.Standard deviation of population s = 10 cmMean of the sample x = 173 cmNumber of the sample n = 50Population mean m = ?
m = ± ¥ =173 170 23 175 771.96 1050
. , .
For about 95% of all samples, the population mean height of university students is between 170.23 cm and 175.77 cm.
Question 8 (b)
Question 8 (c)
Sample 6
Paper 2
132 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
First 10 natural squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
1 2 2 3 56
1 4 306
5 5
2 2+ =× ×
+ =
=
1 2 3 3 4 76
1 4 9 2 714 14
2 2 2+ + =× ×
+ + = ×=
1 2 3 4 4 5 96
1 4 9 16 1806
30 30
2 2 2 2+ + + =× ×
+ + + =
=
1 2 3 4 10 10 11 216
5 11 7 3852 2 2 2 2+ + + + + =× ×
= × × =.......
1 2 3 1 2 16
2 2 2 2+ + + + =+ +....... ( )( )n n n n S100
100 101 2016
338 350= =( )( )
Question 1 (25 marks)Question 1 (a) (i)
sample paper 7: paper 1
Consecutive numbers: n − 1, nConsecutive squares: n n2 21, ( )+n n n n n n n n n2 2 2 2 2 21 2 1 2 1 2 1− − = − − + = − + − = −( ) ( )2n is always an even number2n − 1 is always an odd number
Question 1 (a) (ii)
Question 1 (b) (i) Question 1 (b) (ii) Question 1 (b) (iii)
Question 1 (b) (iv)
Question 1 (c) (i) Question 1 (c) (ii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
A
B(3, 4)
C
O
D
E
5
F
5
3
0.75
3
1.25
x
2.25
3.75
c1
c2
t
θ
�
�
�
�
�
�
θ
θ
y
x P
E(0, 5)F(0, 6.25)D(0, 7)O(0, 10)
c x yc x y
12 2
22 2
10 925
: ( ):
+ − =
+ =
tan.
θ = =5
3 7543
∠ = − − = −
∴ ∠ = − − =
FCB
BCP
180 90 90
90 90
o o o
o o
θ θ
θ θ
( )
( )
θ3
45
sin
cos
( , )
θ
θ
= = ⇒ =
= = ⇒ =
∴
y y
x x
B
545
4
535
3
3 4
Slope of BC = 43
Slope of tangent t = − 34
Equation of t: m x y= − =34 1 1 3 4, ( , ) ( , )
y xy xx y
− = − −
− = − ++ − =
4 34 16 3 93 4 25 0
34 ( )
c x y
t x y x y
y y
12 2
22
10 9
3 4 25 0 25 43
25 43
10
: ( )
:
( )
+ − =
+ − = ⇒ =−
∴−
+ − ==
− ++ − + − =
− + + − +
9
625 200 169
20 100 9 0
625 200 16 9 180 900
22
2 2
y y y y
y y y y −− =
− + =− − =
∴ =
=−
= −
81 025 380 1444 05 38 5 38 0
25 43
2
385
385
y yy yy
x
( )( )
( ) 995
95
385∴ −A( , )
A B
AB
( , ), ( , )
( ) ( )
−
= + + − =
95
385
95
2 385
2
3 4
3 4 6
Question 9 (b)
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
133Higher Level, Educate.ie Sample 7, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
First 10 natural squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
1 2 2 3 56
1 4 306
5 5
2 2+ =× ×
+ =
=
1 2 3 3 4 76
1 4 9 2 714 14
2 2 2+ + =× ×
+ + = ×=
1 2 3 4 4 5 96
1 4 9 16 1806
30 30
2 2 2 2+ + + =× ×
+ + + =
=
1 2 3 4 10 10 11 216
5 11 7 3852 2 2 2 2+ + + + + =× ×
= × × =.......
1 2 3 1 2 16
2 2 2 2+ + + + =+ +....... ( )( )n n n n S100
100 101 2016
338 350= =( )( )
Question 1 (25 marks)Question 1 (a) (i)
sample paper 7: paper 1
Consecutive numbers: n − 1, nConsecutive squares: n n2 21, ( )+n n n n n n n n n2 2 2 2 2 21 2 1 2 1 2 1− − = − − + = − + − = −( ) ( )2n is always an even number2n − 1 is always an odd number
Question 1 (a) (ii)
Question 1 (b) (i) Question 1 (b) (ii) Question 1 (b) (iii)
Question 1 (b) (iv)
Question 1 (c) (i) Question 1 (c) (ii)
LC HigHer LeveL SoLutionS SampLe paper 6 (© Educate.ie)
A
B(3, 4)
C
O
D
E
5
F
5
3
0.75
3
1.25
x
2.25
3.75
c1
c2
t
θ
�
�
�
�
�
�
θ
θ
y
x P
E(0, 5)F(0, 6.25)D(0, 7)O(0, 10)
c x yc x y
12 2
22 2
10 925
: ( ):
+ − =
+ =
tan.
θ = =5
3 7543
∠ = − − = −
∴ ∠ = − − =
FCB
BCP
180 90 90
90 90
o o o
o o
θ θ
θ θ
( )
( )
θ3
45
sin
cos
( , )
θ
θ
= = ⇒ =
= = ⇒ =
∴
y y
x x
B
545
4
535
3
3 4
Slope of BC = 43
Slope of tangent t = − 34
Equation of t: m x y= − =34 1 1 3 4, ( , ) ( , )
y xy xx y
− = − −
− = − ++ − =
4 34 16 3 93 4 25 0
34 ( )
c x y
t x y x y
y y
12 2
22
10 9
3 4 25 0 25 43
25 43
10
: ( )
:
( )
+ − =
+ − = ⇒ =−
∴−
+ − ==
− ++ − + − =
− + + − +
9
625 200 169
20 100 9 0
625 200 16 9 180 900
22
2 2
y y y y
y y y y −− =
− + =− − =
∴ =
=−
= −
81 025 380 1444 05 38 5 38 0
25 43
2
385
385
y yy yy
x
( )( )
( ) 995
95
385∴ −A( , )
A B
AB
( , ), ( , )
( ) ( )
−
= + + − =
95
385
95
2 385
2
3 4
3 4 6
Question 9 (b)
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
Sample 7
Paper 1
134 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
zzz z z
z i
3
3
2
2
11 01 1 0
1 1 4 1 12 1
1 32
1 32
=
− =
− + + =
=− ± −
=− ± −
=− ±
( )( )
( )( )( )
zz i i= − + − −1 12
32
12
32
, ,
1 21 3
21 3
1 31 3
2 2 31 32 2 3
41 3
2
w i
iii
iii
=− +
=− +
×− −− −
=− −
−
=− −
=− −
( )( )( )
ii w2
2=
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
w i
w i i i
=− +
= − + = − −
12
32
14
32
34
12
32
22
Roots
Sum :
Product
: , ,ww
i i
S i i
P
1 12
32
12
32
1 32
1 32
1
=− + − −
− ++− −
= −
:: ww
z Sz Pz zz z
× =
− + =
− − + =
∴ + + =
1 1
01 1 0
1 0
2
2
2
( )
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
S pn qnS p n q n pn pn p qn qS S T T p
n
n
n n n n
= +
= − + − = − + + −
− = ⇒ =−
−
2
12 2
1
1 1 2( ) ( )
nn qn pn pn p qn qpn p q
T p n p qT T p nn
n n
2 2
1
1
22
2 12
+ − + − − += − +
= + − +− = +
+
+
( )( 11 2
2 2 22
) − + − + −= + − + − + −= =
=
p q pn p qpn p p q pn p qp
a T
Common Difference
11
1
22
⇒ = − + = += − =+
a p p q p qd T T pn n
S rr
rr
50 3 3
3
32
2450 25 2 1 49 24500 49 98
2
3 9
= ⇒ + =+ =
=
∴ = =
[ log log ]log
log
Question 2 (25 marks)Question 2 (a)
Question 2 (b) (i) Question 2 (b) (ii)
a ar ara ar ara a r a r
d a
, ,log , log , log
log , log log , log loglog
2
2
2= + += + llog log log
log[ log ( ) log ]
r a ra aS a n rn
n
− === + −2 2 1
135Higher Level, Educate.ie Sample 7, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
zzz z z
z i
3
3
2
2
11 01 1 0
1 1 4 1 12 1
1 32
1 32
=
− =
− + + =
=− ± −
=− ± −
=− ±
( )( )
( )( )( )
zz i i= − + − −1 12
32
12
32
, ,
1 21 3
21 3
1 31 3
2 2 31 32 2 3
41 3
2
w i
iii
iii
=− +
=− +
×− −− −
=− −
−
=− −
=− −
( )( )( )
ii w2
2=
Question 3 (25 marks)Question 3 (a)
Question 3 (b)
w i
w i i i
=− +
= − + = − −
12
32
14
32
34
12
32
22
Roots
Sum :
Product
: , ,ww
i i
S i i
P
1 12
32
12
32
1 32
1 32
1
=− + − −
− ++− −
= −
:: ww
z Sz Pz zz z
× =
− + =
− − + =
∴ + + =
1 1
01 1 0
1 0
2
2
2
( )
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
S pn qnS p n q n pn pn p qn qS S T T p
n
n
n n n n
= +
= − + − = − + + −
− = ⇒ =−
−
2
12 2
1
1 1 2( ) ( )
nn qn pn pn p qn qpn p q
T p n p qT T p nn
n n
2 2
1
1
22
2 12
+ − + − − += − +
= + − +− = +
+
+
( )( 11 2
2 2 22
) − + − + −= + − + − + −= =
=
p q pn p qpn p p q pn p qp
a T
Common Difference
11
1
22
⇒ = − + = += − =+
a p p q p qd T T pn n
S rr
rr
50 3 3
3
32
2450 25 2 1 49 24500 49 98
2
3 9
= ⇒ + =+ =
=
∴ = =
[ log log ]log
log
Question 2 (25 marks)Question 2 (a)
Question 2 (b) (i) Question 2 (b) (ii)
a ar ara ar ara a r a r
d a
, ,log , log , log
log , log log , log loglog
2
2
2= + += + llog log log
log[ log ( ) log ]
r a ra aS a n rn
n
− === + −2 2 1
Sample 7
Paper 1
136 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 5 (25 marks)
f x’( )
x
1 3
6
′ = = + +
∈ ′ ⇒ + + =∴ =
∈ ′ ⇒
f x y ax bx cf x a b c
c
f x
( )( , ) ( ) ( ) ( )
( , ) ( )
2
20 6 0 0 66
1 0 aa ba b
f x a ba
( ) ( )....( )
( , ) ( ) ( ) ( )
1 1 6 06
3 0 3 3 6 09
2
2
+ + =∴ + = −
∈ ′ ⇒ + + =∴
1
++ = −+ = −
− = ⇒ =+ = − ⇒ = −
∴
3 63 2
2 4 22 6 8
ba b
a ab b
....( )
( ) ( ) :( ) ....( )
2
2 11
′′ = = − +f x y x x( ) 2 8 62
Local minimum at x = 3 as dydx
= 0 and the
slope is positive.
Local maximum at x = 1 as dydx
= 0 and the
slope is negative.
f x’( )
x
1 3
6
D
′ = = − +′′ = −′′ = ⇒ − =
∴ =
f x y x xf x xf x xx
( )( )( )
2 8 64 80 4 8 0
2
2
dydx
x x
y x x x cx y cy f x x x x
= − +
= − + +
= = ⇒ =
∴ = = − +
2 8 6
4 60 0 0
4 6
2
23
3 2
23
3 2
,( )
f x x x x
f
( )
( ) ( ) ( ) ( )
= − +
= − + = − + =
23
3 2
23
3 2
4 6
3 3 4 3 6 3 18 36 18 0Local minimmum:
Local maximum:
( , )
( ) ( ) ( ) ( )( ,
3 0
1 1 4 1 6 1 4 61
23
3 2 23
83f = − + = − + =
883
23
3 2 163
432 2 4 2 6 2 16 12
)
( ) ( ) ( ) ( )f = − + = − + =
Point of inflection:: ( , )2 43
Question 5 (a) Question 5 (b)
Question 5 (c)
Question 5 (d) Question 5 (e)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Using the lining up method, a cubic equals a quadratic by a linear.
x px qx r x px q x tx px qx r x tx px ptx q
3 2 2
3 2 3 2 2
3 33 3
+ + + = − + +
+ + + = + − − +
( )( )xx qt
x px qx r x t p x q pt x qt+
+ + + = + − + − +3 2 3 23 3 ( ) ( )
Lining up the coefficients gives you three equations. Replace t from equation (1) in the other equations.
34p t pp t= −=
.....( )1 33 42 4
2
2
2
q q ptq q p pq pq p
= −= −
= −
= −
.....( )( )
..( )
2
i
r qtr q pr pq
===
.....( )( )
34
4
Result (i) is proved under equation (2).To prove result (ii) replace q under equation (3).r pq p p p= = − = −4 4 2 82 3( ) ...( )ii
x px qx r x px q x p3 2 23 3 4+ + + = − + +( )( )
⇒ + + + = − − + = − + + =x px qx r x px p x p x p x p x p3 2 2 23 3 2 4 2 4 0( )( ) ( )( )( )∴ = − −x p p p4 2, ,
Question 4 (25 marks)
Question 4 (a)
Question 4 (b)
Question 4 (c)
137Higher Level, Educate.ie Sample 7, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 5 (25 marks)
f x’( )
x
1 3
6
′ = = + +
∈ ′ ⇒ + + =∴ =
∈ ′ ⇒
f x y ax bx cf x a b c
c
f x
( )( , ) ( ) ( ) ( )
( , ) ( )
2
20 6 0 0 66
1 0 aa ba b
f x a ba
( ) ( )....( )
( , ) ( ) ( ) ( )
1 1 6 06
3 0 3 3 6 09
2
2
+ + =∴ + = −
∈ ′ ⇒ + + =∴
1
++ = −+ = −
− = ⇒ =+ = − ⇒ = −
∴
3 63 2
2 4 22 6 8
ba b
a ab b
....( )
( ) ( ) :( ) ....( )
2
2 11
′′ = = − +f x y x x( ) 2 8 62
Local minimum at x = 3 as dydx
= 0 and the
slope is positive.
Local maximum at x = 1 as dydx
= 0 and the
slope is negative.
f x’( )
x
1 3
6
D
′ = = − +′′ = −′′ = ⇒ − =
∴ =
f x y x xf x xf x xx
( )( )( )
2 8 64 80 4 8 0
2
2
dydx
x x
y x x x cx y cy f x x x x
= − +
= − + +
= = ⇒ =
∴ = = − +
2 8 6
4 60 0 0
4 6
2
23
3 2
23
3 2
,( )
f x x x x
f
( )
( ) ( ) ( ) ( )
= − +
= − + = − + =
23
3 2
23
3 2
4 6
3 3 4 3 6 3 18 36 18 0Local minimmum:
Local maximum:
( , )
( ) ( ) ( ) ( )( ,
3 0
1 1 4 1 6 1 4 61
23
3 2 23
83f = − + = − + =
883
23
3 2 163
432 2 4 2 6 2 16 12
)
( ) ( ) ( ) ( )f = − + = − + =
Point of inflection:: ( , )2 43
Question 5 (a) Question 5 (b)
Question 5 (c)
Question 5 (d) Question 5 (e)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Using the lining up method, a cubic equals a quadratic by a linear.
x px qx r x px q x tx px qx r x tx px ptx q
3 2 2
3 2 3 2 2
3 33 3
+ + + = − + +
+ + + = + − − +
( )( )xx qt
x px qx r x t p x q pt x qt+
+ + + = + − + − +3 2 3 23 3 ( ) ( )
Lining up the coefficients gives you three equations. Replace t from equation (1) in the other equations.
34p t pp t= −=
.....( )1 33 42 4
2
2
2
q q ptq q p pq pq p
= −= −
= −
= −
.....( )( )
..( )
2
i
r qtr q pr pq
===
.....( )( )
34
4
Result (i) is proved under equation (2).To prove result (ii) replace q under equation (3).r pq p p p= = − = −4 4 2 82 3( ) ...( )ii
x px qx r x px q x p3 2 23 3 4+ + + = − + +( )( )
⇒ + + + = − − + = − + + =x px qx r x px p x p x p x p x p3 2 2 23 3 2 4 2 4 0( )( ) ( )( )( )∴ = − −x p p p4 2, ,
Question 4 (25 marks)
Question 4 (a)
Question 4 (b)
Question 4 (c)
Sample 7
Paper 1
138 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Payment # Fixed Payment Interest Debt Payment Balance
0 60 000
1 14 438.07 3900 10 538.07 49 461.93
2 14 438.07 3215.03 11 223.04 38 238.89
3 14 438.07 2485.53 11 952.54 26 286.35
4 14 438.07 1708.61 12 729.46 13 556.89
5 14 438.07 881.20 13 556.87 0
CalCulation for Year 1Payment Number 1: 14 438.07Interest: 60 000 0 065 3900× =.Debt Payment: 14 438 07 3900 00 10 538 07. . .− =Balance: 60000 10538 07 49461 93− =. .
Question 7 (50 marks)Question 7 (a)
Question 7 (b)
Question 7 (c) (i)
Question 7 (c) (ii)
P = + + + + + +250 2501 045
2501 045
2501 045
2501 045
2501 045
251 2 3 4 5. . . . .
001 045
2501 045
250 1 11 045
11 045
11 045
11 045
1
6 7
1 2 3 4
. .
. . . .
+
= + + + + +P11 045
11 045
11 045
1 11 045
8
2501 1
1 04
5 6 7. . .
,.
,
.
+ +
= = =
∴ =
−
a r n
P55
1 11 045
1723 18
8
−
=
.
.
A P i ii
t
t=+
+ −( )
( )1
1 1
P Fi t
=+( )1
P = =5000
1 0453515 938( . )
.
Minimum price = 3515.93 + 1723.18 = 5239.11Minimum price bonds can be offered is 5239 to the nearest euro.
Question 7 (c) (iii)
P t i
A
= = =
=−
=
60 000 5 0 065
60 000 0 065 1 0651 065 1
15
5
, , .. ( . )( . )
years
44 438 07.
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 6 (25 marks)y
x
x = 1
1 4
A
yx
x= − +
32 32
42
yx
x
x
= − +
= − + = − + =
32 32
4
4 324
3 42
4 2 6 4 0
2
2: ( )
A = + + + + + + =0 52
34 5 0 2 15 97 9 5 37 3 06 1 36 26 005. { . ( . . . . )} .
A x x dx
x x x
xx x
= − +
=−
− +
= − − +
−
−
∫ ( )32 4
321
34
4
32 34
4
2 321
4
1 2
1
4
2
= − − +
− − − +
= − −
1
4
2 2324
3 44
4 4 321
3 14
4 1
8
( ) ( ) ( ) ( )
112 16 32 424 75
34
994
+ + + −
= = .
% . ..
% %error = −
× ≈
26 005 24 7524 75
100 5
x 1 1.5 2 2.5 3 3.5 4y 34.5 15.97 9.00 5.37 3.06 1.36 0
Question 6 (a)
Question 6 (b)
Question 6 (c)
Question 6 (d)
139Higher Level, Educate.ie Sample 7, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Payment # Fixed Payment Interest Debt Payment Balance
0 60 000
1 14 438.07 3900 10 538.07 49 461.93
2 14 438.07 3215.03 11 223.04 38 238.89
3 14 438.07 2485.53 11 952.54 26 286.35
4 14 438.07 1708.61 12 729.46 13 556.89
5 14 438.07 881.20 13 556.87 0
CalCulation for Year 1Payment Number 1: 14 438.07Interest: 60 000 0 065 3900× =.Debt Payment: 14 438 07 3900 00 10 538 07. . .− =Balance: 60000 10538 07 49461 93− =. .
Question 7 (50 marks)Question 7 (a)
Question 7 (b)
Question 7 (c) (i)
Question 7 (c) (ii)
P = + + + + + +250 2501 045
2501 045
2501 045
2501 045
2501 045
251 2 3 4 5. . . . .
001 045
2501 045
250 1 11 045
11 045
11 045
11 045
1
6 7
1 2 3 4
. .
. . . .
+
= + + + + +P11 045
11 045
11 045
1 11 045
8
2501 1
1 04
5 6 7. . .
,.
,
.
+ +
= = =
∴ =
−
a r n
P55
1 11 045
1723 18
8
−
=
.
.
A P i ii
t
t=+
+ −( )
( )1
1 1
P Fi t
=+( )1
P = =5000
1 0453515 938( . )
.
Minimum price = 3515.93 + 1723.18 = 5239.11Minimum price bonds can be offered is 5239 to the nearest euro.
Question 7 (c) (iii)
P t i
A
= = =
=−
=
60 000 5 0 065
60 000 0 065 1 0651 065 1
15
5
, , .. ( . )( . )
years
44 438 07.
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 6 (25 marks)y
x
x = 1
1 4
A
yx
x= − +
32 32
42
yx
x
x
= − +
= − + = − + =
32 32
4
4 324
3 42
4 2 6 4 0
2
2: ( )
A = + + + + + + =0 52
34 5 0 2 15 97 9 5 37 3 06 1 36 26 005. { . ( . . . . )} .
A x x dx
x x x
xx x
= − +
=−
− +
= − − +
−
−
∫ ( )32 4
321
34
4
32 34
4
2 321
4
1 2
1
4
2
= − − +
− − − +
= − −
1
4
2 2324
3 44
4 4 321
3 14
4 1
8
( ) ( ) ( ) ( )
112 16 32 424 75
34
994
+ + + −
= = .
% . ..
% %error = −
× ≈
26 005 24 7524 75
100 5
x 1 1.5 2 2.5 3 3.5 4y 34.5 15.97 9.00 5.37 3.06 1.36 0
Question 6 (a)
Question 6 (b)
Question 6 (c)
Question 6 (d)
Sample 7
Paper 1
140 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
pH values: 2 0 2 5 3 02 0 5 6
1 2 5
. , . , . ,......., . ,
( )a d nT a n dn
= = == + − = + (( . ) .0 5 4 5=
pH values: 2.0, 2.5, 3.0, 3.5, 4.0, 4.5.After five hours the pH value is 4.5.
Arithmetic sequence: Geometric sequence:
2 2 5 3 3 510
, . , , . ,....−22 2 5 3
22 5
20 5
8 7
10 10
10 1010
10
10 10
, , ,......
,
.
..
.
− −
−−
−−
− −
= = =
∴ =
a r
22 0 5 1
6 7 0 5 0 5
1010 10
6 7 0 5 0 50 5 0 5 6 7
( )
. . .. . .
.
. . .
− −
− − +=− = − +
= + =
n
n
nn 77 2
7 20 5
14 4
...
.∴ = =n hours
Therefore, the pH value is 8.7 after 13.4 hours.
Question 8 (d) (i)Or
Question 8 (d) (ii)
Question 9 (50 marks)Question 9 (a)
Period
Range
= = =
= −
2200
1100
0 01
10 10
ppp p
min . min
[ , ]
t (minutes) 0 0.0025 0.005 0.0075 0.01 0.0125 0.015 0.0175 0.02
200pt 0p2
p 32p
2p52p
3p72p
4p
sin( )200pt 0 1 0 −1 0 1 0 −1 0
10 200p psin( )t 0 10p 0 -10p 0 10p 0 -10p 0
Question 9 (b)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
pH value [ ]H +
Acidic < 7 > −10 7
Alkaline > 7 < −10 7
Neutral = 7 = −10 7
x yx y x y
+ = ×+ = × ⇒ + =
15 0 40 4 0 25 0 3 15 0 4 0 25 4 5
0
....( )( . ). . . . . . ...( )
12
.. .
. . .. .
4 0 4 60 4 0 25 4 5
0 15 1 5 10
10 15 5
x yx y
y y
x x
+ =+ =
= ⇒ =
+ = ⇒ =
l
l
There is 4.5 l of acid in 15 l of the solution ( . . ).15 0 3 4 5× =When 1 l of water is added, there is now 16 l of solution.
Concentration of acid in solution = × =4 516
100 28 125. % . %
pHpH
= −=
∴ = −
− =
∴ =
+
+
+
− +
log [ ]
log [ ]
log [ ]
[ ]
10
10
107
77
7
10
H
HH
H
Apple juice: moles per litrepH
[ ] .log [ ] log
HH
+
+
=
= − = −
0 00028
10 100
9
0 00028 3 55 7
1 32 10
( . ) . ( )
[ ] .
= <
= ×+ −
Acidic
Ammonia: moles perH litrepH Alkaline= − = − × = >+ −log [ ] log ( . ) . ( )10 10
91 32 10 8 88 7H
Distilled water: pH moles per litre= ⇒ =+ −7 10 7[ ]HpH =
∴ = −
− =
=
∴ = ×
+
+
− +
+
3 223 22
3 22
106
10
103 22
.. log [ ]
. log [ ]
[ ][ ]
.
HH
HH 110 4− moles/litre
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (ii)
Question 8 (b)
Question 8 (c) (i)
Question 8 (c) (ii)
141Higher Level, Educate.ie Sample 7, Paper 1
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
pH values: 2 0 2 5 3 02 0 5 6
1 2 5
. , . , . ,......., . ,
( )a d nT a n dn
= = == + − = + (( . ) .0 5 4 5=
pH values: 2.0, 2.5, 3.0, 3.5, 4.0, 4.5.After five hours the pH value is 4.5.
Arithmetic sequence: Geometric sequence:
2 2 5 3 3 510
, . , , . ,....−22 2 5 3
22 5
20 5
8 7
10 10
10 1010
10
10 10
, , ,......
,
.
..
.
− −
−−
−−
− −
= = =
∴ =
a r
22 0 5 1
6 7 0 5 0 5
1010 10
6 7 0 5 0 50 5 0 5 6 7
( )
. . .. . .
.
. . .
− −
− − +=− = − +
= + =
n
n
nn 77 2
7 20 5
14 4
...
.∴ = =n hours
Therefore, the pH value is 8.7 after 13.4 hours.
Question 8 (d) (i)Or
Question 8 (d) (ii)
Question 9 (50 marks)Question 9 (a)
Period
Range
= = =
= −
2200
1100
0 01
10 10
ppp p
min . min
[ , ]
t (minutes) 0 0.0025 0.005 0.0075 0.01 0.0125 0.015 0.0175 0.02
200pt 0p2
p 32p
2p52p
3p72p
4p
sin( )200pt 0 1 0 −1 0 1 0 −1 0
10 200p psin( )t 0 10p 0 -10p 0 10p 0 -10p 0
Question 9 (b)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
pH value [ ]H +
Acidic < 7 > −10 7
Alkaline > 7 < −10 7
Neutral = 7 = −10 7
x yx y x y
+ = ×+ = × ⇒ + =
15 0 40 4 0 25 0 3 15 0 4 0 25 4 5
0
....( )( . ). . . . . . ...( )
12
.. .
. . .. .
4 0 4 60 4 0 25 4 5
0 15 1 5 10
10 15 5
x yx y
y y
x x
+ =+ =
= ⇒ =
+ = ⇒ =
l
l
There is 4.5 l of acid in 15 l of the solution ( . . ).15 0 3 4 5× =When 1 l of water is added, there is now 16 l of solution.
Concentration of acid in solution = × =4 516
100 28 125. % . %
pHpH
= −=
∴ = −
− =
∴ =
+
+
+
− +
log [ ]
log [ ]
log [ ]
[ ]
10
10
107
77
7
10
H
HH
H
Apple juice: moles per litrepH
[ ] .log [ ] log
HH
+
+
=
= − = −
0 00028
10 100
9
0 00028 3 55 7
1 32 10
( . ) . ( )
[ ] .
= <
= ×+ −
Acidic
Ammonia: moles perH litrepH Alkaline= − = − × = >+ −log [ ] log ( . ) . ( )10 10
91 32 10 8 88 7H
Distilled water: pH moles per litre= ⇒ =+ −7 10 7[ ]HpH =
∴ = −
− =
=
∴ = ×
+
+
− +
+
3 223 22
3 22
106
10
103 22
.. log [ ]
. log [ ]
[ ][ ]
.
HH
HH 110 4− moles/litre
Question 8 (50 marks)Question 8 (a) (i)
Question 8 (a) (ii)
Question 8 (b)
Question 8 (c) (i)
Question 8 (c) (ii)
Sample 7
Paper 1
142 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A( 5, 8)�
B(3, 8)�
C( , 2)�
ABC
( , ) ( , )( , ) ( , )( , ) ( , )
( ) (
− →− → −→ −
= − −
5 8 0 03 8 8 166 2 11 6
8 6 1112Area −− = − + = =16 48 176 128 641
212)
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
B CA D
( , ) ( , )( , ) ( , )3 8 6 2
5 8 2 18− →
− → −
Equation of BC: B C
m x y
y x
( , ), ( , )( ) , ( , ) ( , )
( ) (
3 8 6 22 8
6 3103
3 8
8 3
1 1
103
−
=− −−
= = −
− − = − ))3 24 10 3010 3 54 0y xx y+ = −− − =
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
d
d =− − −
+ −=
10 2 3 18 54
10 31281092 2
( ) ( )
( )
Question 1 (25 marks)Question 1 (a)
sample paper 7: paper 2
Area = −12 1 2 2 1x y x y
Question 1 (b)
y y m x x− = −1 1( )
B C
CB
( , ), ( , )
( ) ( ( ))
3 8 6 2
6 3 2 8 1092 2
−= ×
= − + − − =
Area Base Height
Base:
AArea = × =109 128109
128
dax by c
a b=
+ +
+1 1
2 2
or
Area of parallelogram ABCD = 2(Area of triangle ABC)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
(i) Breathing in: 0 s − 0.0025 s, 0.0075 s − 0.0125 s, 0.0175 s − 0.02 s(ii) Breathing out: 0.0025 s − 0.0075 s, 0.0125 s − 0.0175 s(iii) Maximum values: 0.0025 s, 0.0125 s
Question 9 (c)
dVdt
t
dV t dt
V t
=
=
= −
∫ ∫
10 200
10 200
10200
200
p p
p p
pp
p
sin( )
sin( )
cos( ) ++
= − += = = − +
c
V t ct V c
0 05 2000 2 95 2 95 0 05 200 0
2
. cos( ), . : . . cos( ( ))
pp
.. .
. cos( )
95 0 0530 05 200 3
= − +∴ == − +
cc
V tp
V t
V t d
= − +
=−
− +∫
0 05 200 31
0 01 00 05 200 3
0
0 01
. cos( )
.( . cos( ) )
.
p
pAve. tt
t t= −
= −
100 3 0 5200
200
100 3 0 01 0 05200
0
0 01. sin( )
( . ) . s
.
pp
piin( ( . ))
. sin( )
200 0 01 0
3 0 05200
2
3
p
pp
−
= −
= litres
Question 9 (d) Question 9 (e)
00.01 0.015 0.02
2�
4�
6�
8�
10�
����2
�4�
�6�
�8�
�10�
M
t (minutes)0.005
R (litres/minute)
M
143Higher Level, Educate.ie Sample 7, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A( 5, 8)�
B(3, 8)�
C( , 2)�
ABC
( , ) ( , )( , ) ( , )( , ) ( , )
( ) (
− →− → −→ −
= − −
5 8 0 03 8 8 166 2 11 6
8 6 1112Area −− = − + = =16 48 176 128 641
212)
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
B CA D
( , ) ( , )( , ) ( , )3 8 6 2
5 8 2 18− →
− → −
Equation of BC: B C
m x y
y x
( , ), ( , )( ) , ( , ) ( , )
( ) (
3 8 6 22 8
6 3103
3 8
8 3
1 1
103
−
=− −−
= = −
− − = − ))3 24 10 3010 3 54 0y xx y+ = −− − =
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
d
d =− − −
+ −=
10 2 3 18 54
10 31281092 2
( ) ( )
( )
Question 1 (25 marks)Question 1 (a)
sample paper 7: paper 2
Area = −12 1 2 2 1x y x y
Question 1 (b)
y y m x x− = −1 1( )
B C
CB
( , ), ( , )
( ) ( ( ))
3 8 6 2
6 3 2 8 1092 2
−= ×
= − + − − =
Area Base Height
Base:
AArea = × =109 128109
128
dax by c
a b=
+ +
+1 1
2 2
or
Area of parallelogram ABCD = 2(Area of triangle ABC)
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
(i) Breathing in: 0 s − 0.0025 s, 0.0075 s − 0.0125 s, 0.0175 s − 0.02 s(ii) Breathing out: 0.0025 s − 0.0075 s, 0.0125 s − 0.0175 s(iii) Maximum values: 0.0025 s, 0.0125 s
Question 9 (c)
dVdt
t
dV t dt
V t
=
=
= −
∫ ∫
10 200
10 200
10200
200
p p
p p
pp
p
sin( )
sin( )
cos( ) ++
= − += = = − +
c
V t ct V c
0 05 2000 2 95 2 95 0 05 200 0
2
. cos( ), . : . . cos( ( ))
pp
.. .
. cos( )
95 0 0530 05 200 3
= − +∴ == − +
cc
V tp
V t
V t d
= − +
=−
− +∫
0 05 200 31
0 01 00 05 200 3
0
0 01
. cos( )
.( . cos( ) )
.
p
pAve. tt
t t= −
= −
100 3 0 5200
200
100 3 0 01 0 05200
0
0 01. sin( )
( . ) . s
.
pp
piin( ( . ))
. sin( )
200 0 01 0
3 0 05200
2
3
p
pp
−
= −
= litres
Question 9 (d) Question 9 (e)
00.01 0.015 0.02
2�
4�
6�
8�
10�
����2
�4�
�6�
�8�
�10�
M
t (minutes)0.005
R (litres/minute)
M
Sample 7
Paper 2
144 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
135o
45o
A(2, 6)
B
O
y
x
k
Line k makes an angle of 45o with the positive x-axis. The slope of k is the tan of the angle the line makes with the positive x-axis.
tan , ( , ) ( , )( )
:
45 1 2 66 1 26 2
4 0
1 1o = = =
− = −− = −− + =
m x y Ay xy xk x y
P( 1, 2)�
Q x y( , )O(0, 0)
x y y xQ x y x xP
x x
x
+ − = ⇒ = −= −
−
= − − − =
∴
1 0 11
1 22 1 1 7
2
12
( , ) ( , )( , )
( )( )Area
++ − =
+ =
+ = ±
∴ = − >= − = −
∴ −
1 14
1 141 14
13 15 01 1213 12
x
xx
x xy xQ
, ( )
( , )
The midpoint of [PQ] is the centre of the circle. Call it R.
P Q
R
( , ), ( , )
, ( , )
− −
=− + −
= −
1 2 13 121 13
22 12
26 5
Equation of circle:
P R
r PR
( , ), ( , )
( ) ( )
− −
= = + + − − = + =
1 2 6 5
6 1 5 2 49 49 7 22 2
( ) ( )( ) ( )x h y k rx y− + − =
− + + =
2 2 2
2 26 5 98
Question 2 (25 marks)
Question 2 (a)
y y m x x− = −1 1( )
Area = −12 1 2 2 1x y x y
Question 2 (b)
Question 2 (c)
R( , 5)����
Q(13, 12)� O(0, 0)
P( 1, 2)�
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
�
�
Slope of AC: m18 25 6
611
=−
− −= −
Slope of BD: m218 8
2 3265
=+
− −= −
tan( )( )
tan
θ
θ
= +−
+
=
− ++ −
∴ =− +−
m mm m
1 2
1 2
611
265
611
265
16
11
1 12265
611
2651
50 5+ −
=( )( )
. o
Question 1 (c)
145Higher Level, Educate.ie Sample 7, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
135o
45o
A(2, 6)
B
O
y
x
k
Line k makes an angle of 45o with the positive x-axis. The slope of k is the tan of the angle the line makes with the positive x-axis.
tan , ( , ) ( , )( )
:
45 1 2 66 1 26 2
4 0
1 1o = = =
− = −− = −− + =
m x y Ay xy xk x y
P( 1, 2)�
Q x y( , )O(0, 0)
x y y xQ x y x xP
x x
x
+ − = ⇒ = −= −
−
= − − − =
∴
1 0 11
1 22 1 1 7
2
12
( , ) ( , )( , )
( )( )Area
++ − =
+ =
+ = ±
∴ = − >= − = −
∴ −
1 14
1 141 14
13 15 01 1213 12
x
xx
x xy xQ
, ( )
( , )
The midpoint of [PQ] is the centre of the circle. Call it R.
P Q
R
( , ), ( , )
, ( , )
− −
=− + −
= −
1 2 13 121 13
22 12
26 5
Equation of circle:
P R
r PR
( , ), ( , )
( ) ( )
− −
= = + + − − = + =
1 2 6 5
6 1 5 2 49 49 7 22 2
( ) ( )( ) ( )x h y k rx y− + − =
− + + =
2 2 2
2 26 5 98
Question 2 (25 marks)
Question 2 (a)
y y m x x− = −1 1( )
Area = −12 1 2 2 1x y x y
Question 2 (b)
Question 2 (c)
R( , 5)����
Q(13, 12)� O(0, 0)
P( 1, 2)�
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A( 5, 8)�
B(3, 8)�C( , 2)�
D( , 18)��
�
�
Slope of AC: m18 25 6
611
=−
− −= −
Slope of BD: m218 8
2 3265
=+
− −= −
tan( )( )
tan
θ
θ
= +−
+
=
− ++ −
∴ =− +−
m mm m
1 2
1 2
611
265
611
265
16
11
1 12265
611
2651
50 5+ −
=( )( )
. o
Question 1 (c)
Sample 7
Paper 2
146 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A spinner has nine equal segments numbered 1, 2, 3, 4, 5, 6, 7, 8 and 9 (Nine numbers)Blue: 2, 3, 6, 8, 9 (Five numbers) Red: 1, 4, 5, 7 (Four numbers)E is the event that the pointer lands on an even number. E: 2, 4, 6, 8 (Four numbers)R is the event that the pointer lands on a red colour.
P E R P E P R P E RE R
P E R
( ) ( ) ( ) ( ){ }
( )
∪ = + − ∩∩ =
∪ = + − =
449
49
19
79
R
6
E
2
84
3
1
9
57
P R E P R EP E
( | ) ( )( )
=∩
= = × =1949
19
94
14
P E R P E RP R
( | ) ( )( )
=∩
= = × =1949
19
94
14
(i) Yes, because P(E) = P(R), (ii) No: 1
449π
Question 4 (25 marks)
Question 4 (a)
Question 4 (b)
Question 4 (c)
Question 4 (d)
Question 4 (e)
Question 4 (f)
P E( ) = =Number of even numbers
Number of numbers49
P R( ) = =Number of red colours
Number of numbers49
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
y x x
x
=
=
sin cos
, , , , , , , , ,
3 2
04 3
23
34
54
43
53
74
π π π ππ
π π π π
x
y
p q r
p
q
r
=
=
=
π
ππ
3
54
( )
( )
( )
Third root
Sixth root
Seventh root
T C
S Ay = 25
x
1
cos x = + =15
AdjacentHypotenuse
The angle x is located in the first and fourth quadrants.
1 55 1 42
2 2 2
2
+ =
= − =∴ =
yy
y
( )
tan ( )
tan tantan
tan
x
x xx
x
= ±
=−
=
2
2 21 2
First and fourth quadrants
22 2 2 21 2
43
2 2 2 21 2
43
2
2
: tan ( )
tan : tan ( )( )
x
x x
=−
= −
= − =−
− −=
T C
S A
T C
S A
sin 3x = 0 cos 2x = 0
Question 3 (25 marks)Question 3 (a)
Question 3 (b) (i)
Question 3 (b) (ii)
3 0 2 2
23 3
23
03
23
43
53
x n n n
x n n n
x
= + + ∈
= + ∈
=
π π π
π π π
π ππ
π π
, ,
, ,
, , , , ,
�
�
22
2 32
2
434
434
54
74
x n n n
x n n n
x
= + + ∈
= + + ∈
=
ππ
ππ
ππ
ππ
π π π π
, ,
, ,
, , ,
�
�
147Higher Level, Educate.ie Sample 7, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
A spinner has nine equal segments numbered 1, 2, 3, 4, 5, 6, 7, 8 and 9 (Nine numbers)Blue: 2, 3, 6, 8, 9 (Five numbers) Red: 1, 4, 5, 7 (Four numbers)E is the event that the pointer lands on an even number. E: 2, 4, 6, 8 (Four numbers)R is the event that the pointer lands on a red colour.
P E R P E P R P E RE R
P E R
( ) ( ) ( ) ( ){ }
( )
∪ = + − ∩∩ =
∪ = + − =
449
49
19
79
R
6
E
2
84
3
1
9
57
P R E P R EP E
( | ) ( )( )
=∩
= = × =1949
19
94
14
P E R P E RP R
( | ) ( )( )
=∩
= = × =1949
19
94
14
(i) Yes, because P(E) = P(R), (ii) No: 1
449π
Question 4 (25 marks)
Question 4 (a)
Question 4 (b)
Question 4 (c)
Question 4 (d)
Question 4 (e)
Question 4 (f)
P E( ) = =Number of even numbers
Number of numbers49
P R( ) = =Number of red colours
Number of numbers49
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
y x x
x
=
=
sin cos
, , , , , , , , ,
3 2
04 3
23
34
54
43
53
74
π π π ππ
π π π π
x
y
p q r
p
q
r
=
=
=
π
ππ
3
54
( )
( )
( )
Third root
Sixth root
Seventh root
T C
S Ay = 25
x
1
cos x = + =15
AdjacentHypotenuse
The angle x is located in the first and fourth quadrants.
1 55 1 42
2 2 2
2
+ =
= − =∴ =
yy
y
( )
tan ( )
tan tantan
tan
x
x xx
x
= ±
=−
=
2
2 21 2
First and fourth quadrants
22 2 2 21 2
43
2 2 2 21 2
43
2
2
: tan ( )
tan : tan ( )( )
x
x x
=−
= −
= − =−
− −=
T C
S A
T C
S A
sin 3x = 0 cos 2x = 0
Question 3 (25 marks)Question 3 (a)
Question 3 (b) (i)
Question 3 (b) (ii)
3 0 2 2
23 3
23
03
23
43
53
x n n n
x n n n
x
= + + ∈
= + ∈
=
π π π
π π π
π ππ
π π
, ,
, ,
, , , , ,
�
�
22
2 32
2
434
434
54
74
x n n n
x n n n
x
= + + ∈
= + + ∈
=
ππ
ππ
ππ
ππ
π π π π
, ,
, ,
, , ,
�
�
Sample 7
Paper 2
148 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
B
A
C
D
E
**
∠ = ∠
∠ = ∠
DEA BEC
EAD CBE
( )
(
Vertically opposite
Standing on same arcc)
∴∠ = ∠ADE BCE
AEDE
BEEC
AE EC BE DE
=
∴ =
Question 6 (25 marks)Question 6 (a) (i)
Question 6 (a) (ii)
Question 6A (b)
r
r2�
G
F
H
I
OJ
2
4
3
FJ JH IJ JGr r
rr
r
=
× = − +
= −
=∴ =
3 4 2 212 416
4
2
2
( )( )
(i) The distribution is normal.
µ σµ σµ µ
σ σ
+ =− =
= ⇒ =
+ = ⇒ =
2 108 62 97 4
2 206 103
103 2 108 6 2 8
..
. .
g
g
µ σ
µσ
= =< =
= =−
=−
= −
<
103 2 8100
100 100 1032 8
1 07
10
g, g.( ) ?
:.
.
(
P x
x z x
P x 00 1 071 07
1 1 071 0 85770 142314 23
) ( . )( . )
( . ).
..
= < −= >= − <= −==
P zP zP z
%%
Question 7 (45 marks)Question 7 (a)
(ii)
Question 7 (b) Question 7 (c)P xP x ZP z ZP z Zz
( ) .( ) .( ) .( ) .
.
< =< − => =< =
∴ =
100 0 0010 001
0 0010 999
3 08⇒⇒ − = −
− =−
∴ =
zx
x
30 8
3 08 1002 8
108 624
.
..
. g
Weight in grams97.4 g 108.6 g
95%
µ
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
400030002000
1000
60005000
Cum
ula
tive f
requency
900
600
500
400
300
200
100
800
700
0
IQ Range
1000
Weight (grams)Median10 percentile
th.
Median = 3400 gInterquartile range = 3670 − 3060 = 610 g
n P P= =12 0 15, ( ) . , ( )Need special care Do not need special care ==
= =
0 850 15 0 85 0 292412
22 10
. ,( ) ( . ) ( . ) .P C2 need special care
E = × =100 0 2641 26 41. . occasions
Question 5 (25 marks)Question 5 (a)
Range of weights below the 10th. percentile = 0−2600 gQuestion 5 (b)
Question 5 (c) (i)
Question 5 (c) (ii)
A.
B. P P( ) (More than two need special care Two or one or none nee= −1 dd special care){ . ( . ) ( . ) ( . )= − + +1 0 2924 0 15 0 85 0 1512
11 11 12
00C C (( . ) }
.0 85
0 2641
12
=
149Higher Level, Educate.ie Sample 7, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
B
A
C
D
E
**
∠ = ∠
∠ = ∠
DEA BEC
EAD CBE
( )
(
Vertically opposite
Standing on same arcc)
∴∠ = ∠ADE BCE
AEDE
BEEC
AE EC BE DE
=
∴ =
Question 6 (25 marks)Question 6 (a) (i)
Question 6 (a) (ii)
Question 6A (b)
r
r2�
G
F
H
I
OJ
2
4
3
FJ JH IJ JGr r
rr
r
=
× = − +
= −
=∴ =
3 4 2 212 416
4
2
2
( )( )
(i) The distribution is normal.
µ σµ σµ µ
σ σ
+ =− =
= ⇒ =
+ = ⇒ =
2 108 62 97 4
2 206 103
103 2 108 6 2 8
..
. .
g
g
µ σ
µσ
= =< =
= =−
=−
= −
<
103 2 8100
100 100 1032 8
1 07
10
g, g.( ) ?
:.
.
(
P x
x z x
P x 00 1 071 07
1 1 071 0 85770 142314 23
) ( . )( . )
( . ).
..
= < −= >= − <= −==
P zP zP z
%%
Question 7 (45 marks)Question 7 (a)
(ii)
Question 7 (b) Question 7 (c)P xP x ZP z ZP z Zz
( ) .( ) .( ) .( ) .
.
< =< − => =< =
∴ =
100 0 0010 001
0 0010 999
3 08⇒⇒ − = −
− =−
∴ =
zx
x
30 8
3 08 1002 8
108 624
.
..
. g
Weight in grams97.4 g 108.6 g
95%
µ
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
400030002000
1000
60005000
Cum
ula
tive f
requency
900
600
500
400
300
200
100
800
700
0
IQ Range
1000
Weight (grams)Median10 percentile
th.
Median = 3400 gInterquartile range = 3670 − 3060 = 610 g
n P P= =12 0 15, ( ) . , ( )Need special care Do not need special care ==
= =
0 850 15 0 85 0 292412
22 10
. ,( ) ( . ) ( . ) .P C2 need special care
E = × =100 0 2641 26 41. . occasions
Question 5 (25 marks)Question 5 (a)
Range of weights below the 10th. percentile = 0−2600 gQuestion 5 (b)
Question 5 (c) (i)
Question 5 (c) (ii)
A.
B. P P( ) (More than two need special care Two or one or none nee= −1 dd special care){ . ( . ) ( . ) ( . )= − + +1 0 2924 0 15 0 85 0 1512
11 11 12
00C C (( . ) }
.0 85
0 2641
12
=
Sample 7
Paper 2
150 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
x
y
M
= = × =
= = × =
∴
10 2 45 10 2 12
10
10 2 45 10 2 12
10
10 10
cos
sin
( , )
o
o
km
km
Bearing of Ships A and B:
The ships travelling from O are moving along tangents to the circle with centre M(10, 10) of radius 2 km. This is analogous to the previous circle. You know the slopes of these two tangents.
dax by c
a b=
+ +
+1 1
2 2
Equation of circle:
x y x yg f
r g f c
2 2
2 2
20 20 196 010 10
100 100
+ − − + == − − =
= + − = +
Centre ( , ) ( , )
−− = =196 4 2
(0, 0)
(10, 10)
r = 2
r = 2
mx y = 0�
Slope of tangent = m.
Question 9 (65 marks)Question 9 (a) (i) Question 9 (a) (ii)
Question 9 (b)
Question 9 (c)
Question 9 (d)
Equation of tangent :
Equation of tang
t mx y kt k
− + =∈ ⇒ =
00 0 0( , )
eent : t mx ymx y x y d
m
m
m
− =− = = =
=−
+
00 10 10 2
210 10
1
2
1 1
2
, ( , ) ( , ),( ) ( )
22
2
1 10 1
1 5 1
+ = −
+ = −
m
m m
m mm m m
m mm mm
2 2
2 2
2
2
1 25 11 25 50 25
24 50 24 012 25 12 04
+ = −
+ = − +
− + =
− + =
( )
( −− − =∴ =
3 3 4 034
43
)( ),
mm
tan
tan ( ) .
α
α
= =
∴ = =−
m 34
1 34 36 87o N of E
tan
tan ( ) .
β
β
= =
∴ = =−
m 43
1 43 53 13o N of E
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 7 (d)PP
( ) .(Less than advertised weightNot less than advertised
= 0 1423 weight
At least one weighs less than advertised) .
(= 0 8577
P weightOne or more weighs less than advertised weight
)(= P ))
( )( .
= −
= −
11 0 14235
0
PC
None with less than advertised weight)) ( . )
.. %
0 50 85770 53653 6
==
Question 8 (40 marks)Question 8 (a)The parameter in this question is the mean glass thickness, m.Null hypothesis H0: m = 0.954 cmAlternative hypothesis HA: m ≠ 0.954 cm(This is called a two-tailed test as the glass should not be too thick or too thin.)
Question 8 (b)
z x
n
= -ÊËÁ
ˆ¯̃
ms
Mean m = 0.954 cmMean of sample x = 0 96. cmStandard deviation s = 0.13 cmNumber of sample n = 100z = ?
z = -ÊËÁ
ˆ¯̃
=0 96 0 9540 13100
0 46. ..
.
Question 8 (c)p P z= >
= - -= -=
2 0 462 0 5 0 6772 0 52 1 0 67720 6456 0 05
( . ){ . ( . . )}{ . }. .� [0.05 = 5% level of significance]
Therefore, the probability of the null hypothesis is very, very strong. We accept the null hypothesis.
Question 8 (d)The glass company does not have sufficient evidence to conclude it is not meeting the specifications. The difference between the sample mean and the actual mean is not large enough to attribute to anything but sampling error.
151Higher Level, Educate.ie Sample 7, Paper 2
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
x
y
M
= = × =
= = × =
∴
10 2 45 10 2 12
10
10 2 45 10 2 12
10
10 10
cos
sin
( , )
o
o
km
km
Bearing of Ships A and B:
The ships travelling from O are moving along tangents to the circle with centre M(10, 10) of radius 2 km. This is analogous to the previous circle. You know the slopes of these two tangents.
dax by c
a b=
+ +
+1 1
2 2
Equation of circle:
x y x yg f
r g f c
2 2
2 2
20 20 196 010 10
100 100
+ − − + == − − =
= + − = +
Centre ( , ) ( , )
−− = =196 4 2
(0, 0)
(10, 10)
r = 2
r = 2
mx y = 0�
Slope of tangent = m.
Question 9 (65 marks)Question 9 (a) (i) Question 9 (a) (ii)
Question 9 (b)
Question 9 (c)
Question 9 (d)
Equation of tangent :
Equation of tang
t mx y kt k
− + =∈ ⇒ =
00 0 0( , )
eent : t mx ymx y x y d
m
m
m
− =− = = =
=−
+
00 10 10 2
210 10
1
2
1 1
2
, ( , ) ( , ),( ) ( )
22
2
1 10 1
1 5 1
+ = −
+ = −
m
m m
m mm m m
m mm mm
2 2
2 2
2
2
1 25 11 25 50 25
24 50 24 012 25 12 04
+ = −
+ = − +
− + =
− + =
( )
( −− − =∴ =
3 3 4 034
43
)( ),
mm
tan
tan ( ) .
α
α
= =
∴ = =−
m 34
1 34 36 87o N of E
tan
tan ( ) .
β
β
= =
∴ = =−
m 43
1 43 53 13o N of E
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Question 7 (d)PP
( ) .(Less than advertised weightNot less than advertised
= 0 1423 weight
At least one weighs less than advertised) .
(= 0 8577
P weightOne or more weighs less than advertised weight
)(= P ))
( )( .
= −
= −
11 0 14235
0
PC
None with less than advertised weight)) ( . )
.. %
0 50 85770 53653 6
==
Question 8 (40 marks)Question 8 (a)The parameter in this question is the mean glass thickness, m.Null hypothesis H0: m = 0.954 cmAlternative hypothesis HA: m ≠ 0.954 cm(This is called a two-tailed test as the glass should not be too thick or too thin.)
Question 8 (b)
z x
n
= -ÊËÁ
ˆ¯̃
ms
Mean m = 0.954 cmMean of sample x = 0 96. cmStandard deviation s = 0.13 cmNumber of sample n = 100z = ?
z = -ÊËÁ
ˆ¯̃
=0 96 0 9540 13100
0 46. ..
.
Question 8 (c)p P z= >
= - -= -=
2 0 462 0 5 0 6772 0 52 1 0 67720 6456 0 05
( . ){ . ( . . )}{ . }. .� [0.05 = 5% level of significance]
Therefore, the probability of the null hypothesis is very, very strong. We accept the null hypothesis.
Question 8 (d)The glass company does not have sufficient evidence to conclude it is not meeting the specifications. The difference between the sample mean and the actual mean is not large enough to attribute to anything but sampling error.
Sample 7
Paper 2
152 Mathematics Leaving Certificate
LC HigHer LeveL SoLutionS SampLe paper 7 (© Educate.ie)
Distances travelled by A and B:Question 9 (e)
Question 9 (f)
θ24
725
tan cosθ θ= ⇒ =724
2425
θ
l
80 km60 km
O
l
l
2 2 2
2 2 2425
60 80 2 60 80
60 80 2 60 80 28
= + −
= + − =
( )( ) cos
( )( )( )
θ
km
Question 9 (g)
v tsB = == × =
30 230 2 60
km/h hkm
,
v st
s v t
v tsA
= ⇒ = ×
= == × =
40 240 2 80
km/h hkm
,
m m143 2
34
43
34
43
34
43
34
4
1 1 1
= =
∴ = +−
+
= +
−+
= +
,
tan( )( )
θ 3334
43
34
2
21212
16 924
724
−
=−
×
=−
=