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Trng i hc Bch khoa tp. HCh MinhBmn Ton ng dng
-------------------------------------------------------------------------------------
i stuyn tnh
1
Ging vin Ts.ng Vn Vinh (9/2008)www.tanbachkhoa.edu.vn
Mn hc cung cp cc kin thc cbn ca i stuyn tnh. Sinh vinsau khi kt thc mn hc nm vng cc kin thc nn tng v bit giicc bi ton cbn: tnh nh thc, lm vic vi ma trn, bi ton gii
Mc tiu ca mn hc Ton 2
2
hphng trnh tuy n tnh, khng gian vct, nh xtuy n tnh, tm trring vc tring, a dng ton phng vchnh tc.
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Sphc
Ma trn
nh thc
Hphng trnh tuyn tnh
3
Khng gian vc t
Php bin i tuyn tnh
Trring, vctring
Dng ton phng
Khng gian Euclide
Nhim vca sinh vin.
i hc y .
Lm tt ccc bi tp cho vnh.
c bi mi trc khi n lp.
4
nh gi, ki m tra.
Thi gia hc k: hnh thc trc nghim (20%)
Thi cui k: tlun (80%)
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Ti liu tham kho
1.Cng Khanh, Ng Thu Lng, Nguyn Minh Hng.i stuyn tnh. NXBi hc quc gia
2. Ng Thu Lng, Nguyn Minh Hng. Bi tp ton caocp 2.
5
11.www.tanbachkhoa.edu.vn
3.Cng Khanh.i stuyn tnh. NXBH quc gia
Ni dung--------------------------------------------------------------------------------------------------------------------
0.1 Dngi sca sphc
0.2 Dng lng gic ca sphc
0.3 Dng mca sphc
6
0.4 Nng sphc ln ly tha
0.5 Khai cn sphc
0.6 nh l cbn cai s
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0.1 Dng i sca sphc-------------------------------------------------------------------------------------------------------------------
Khng tn ti mt s thc no m bnh phng ca n l mt sm. Hay, khng tn ti s thcx sao chox2 = -1.
Bnh phng ca mt s o l mt s m. K tic chn k
th k th 17, ngi tanh ngha mt s o.
7
nh ngha si
Si,c gi ln v o, l mt s sao cho
i2
= -1
hiu mt s m bnh phng ca n b ng1.
0.1 Dng i sca sphc-----------------------------------------------------------------
nh ngha s phcChoa vb l hai s thc vi ln v o, khi z = a + bi
c gi l s phc. S thca c gi l phn thc v sthcbc gi l phno ca s phcz.
8
Tp s thc l tp hp con ca tp s phc, bi v nu cho b = 0,tha + bi = a + 0i = a l mt s phc.
Phn thc ca s phcz = a + bic k hiu lRe(z).Phno ca s phcz = a + bic k hiu lIm(z).
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0.1 Dng i sca sphc-----------------------------------------------------------------
Tt c cc s c dng 0 + bi, vi b l mt s thc khc khng
c gi l s thuno. V d:i, -2i, 3i l nhng s thuno.
9
S phc ghidng z = a + bic gi l dngi s ca sphcz.
0.1 Dng i sca sphc
-----------------------------------------------------------------
nh ngha php nhn hai s phc.Cho z1= a + bi vz2= c + di l hai s phc, khi
z1.z2= (a + bi) (c + di) = (ac bd) + ( ad + bc)i
V dTm d n i s ca s hc
10
z = (2 + 5i).(3+ 2i)
Gii
z = (2 + 5i)(3 + 2i)
= 6 + 4i + 15i + 10 i2
Vy dngi s ca s phc l: z = -4 + 19i.
= 2.3 + 2.2i + 3.5i + 5i.2i
= 6 + 19i + 10(-1) = -4 + 19i
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0.1 Dng i sca sphc-----------------------------------------------------------------
Hai sphc c gi l bng nhau nu chng c phn thc v phno tng ng bng nhau.
Ni cch khc, hai sphcz1= a1+ ib1 vz2= a2+ib2 bng nhaukhi v chkhi a1= a2 v b1= b2.
nh ngha sbng nhau
11
Choz1= 2 + 3i; z2= m + 3i.
Tm tt c cc s thcmz1= z2.
Gii
1 2 2 3 3z z i m i= + = +2
23 3
mm
= =
=
0.1 Dng i sca sphc
-----------------------------------------------------------------nh ngha php cng v php tr ca hai s phc.Choa + bi vc + di l hai s phc, khi
Php cng: (a + bi) + (c + di) = (a + c) + (b + d) i
Php tr: (a + bi) - (c + di) = (a - c) + (b - d) i
V d
12
Tm ph n thc v ph no ca s phcz = (3 + 5i) + (2 - 3i).
Giiz = (3 + 5i) + (2 - 3i)
Re( ) 5; Im( ) 2.z z = =
= (3+2) + (5i 3i) = 5 + 2i.
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0.1 Dng i sca sphc-----------------------------------------------------------------
Choz vw l hai s phc; v l hai s phc lin hptngng. Khi:
z w
1. l mt s thc.z z+
2. l mt s thc.z z
Tnh cht ca s phc lin hp
13
3. khi v ch khiz l mt s thc.z z=
4. z w z w+ = +
5. z w z w =
6. z z=
7. vi mi s t nhinn( )n nz z=
0.1 Dng i sca sphc
-----------------------------------------------------------------
Cng, tr, nhn hai sphc:Khi cng (tr) hai sphc, ta cng (tr) phn thc v
phn o tng ng.
14
N n a s p c, ta t c n g ng n n n a uthc i svi ch i2 = 1.
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0.1 Dng i sca sphc-----------------------------------------------------------------
V d.
nh ngha s phc lin hp
S phc c gi l s phc lin hp ca sphcz =a + bi.
z a bi=
15
Tm s phc lin hp ca s phcz = (2 + 3i) (4 - 2i).
Gii.
Vy s phc lin hp l 14 8 .= z i
z = (2 + 3i) (4 - 2i) =2.4 2.2i + 3i.4 3i.2i
=8 4i + 12i 6i2
= 8 4i + 12i 6(-1) = 14 + 8i.
Lu : So snh vi sphc.Trong trng sphc khng c khi nim so snh. Ni mt cchkhc, khng thso snh hai sphcz1 = a1 + ib1 v z2 = a2 + ib2
0.1 Dng i s ca s phc------------------------------------------------------------------
16
. 1 2 2 1
ngha trong trng sphc C ngoi trchng ta nh ngha khinim so snh mt cch khc.
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0.1 Dng i sca sphc-----------------------------------------------------------------
Php chia hai s phc.
1 1 12 2 2
z a ib
z a ib
+
=+
17
2 2 2 2 2( )( )z a ib a ib=
+
1 1 2 1 2 1 2 2 12 2 2 2
2 2 2 2 2
z a a b b b a a bi
z a b a b
+ = +
+ +
Mun chia sphc z1 cho z2, ta nhn tv mu cho sphc lin hpca mu. (Gis )2 0z
0.1 Dng i s ca s phc-----------------------------------------------------------------
V d.
Thc hin php toni
i
+
5
23
Gii.Nhn t v mu cho s phc
18
)5)(5(5 iii +=
125
210315 2
+
+++=
iii
ii
2
1
2
1
26
1313+=
+=
n p c a m u + .
Vitdngi s
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0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
( , ) = +M a b z a bib
y
trco
19
r
ao x
2 2 mod( )= + =r a b z
cos
:sin
=
=
a
r
b
r
trc thc
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
2 2mod( ) | |= = +z z a b
nh ngha Mdun ca s phcMdun ca s phcz = a + bi l mt s thc dngcnh nghanh sau:
V d
20
Tm mun ca s phcz = 3 - 4i.
Gii
Vy mod(z) =|z| = 2 2 2 23 ( 4) 5.+ = + =a ba = 3; b = -4.
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0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
Ch :
Nu coi s phcz = a + bi l mtim c ta (a, b), th2 2 2 2| | ( 0) ( 0)= + = + z a b a b
l khong cch t im (a, b)n gc ta.
21
Choz = a + bi v w = c + di.
l khong cch gia haiim (a, b) v (c,d).
2 2| | ( ) ( )z w a c b d = +
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Tm tt c cc s phc z t ha
| 2 3 | 5 + =z i
22
| 2 3 | 5z i + =
| (2 3 ) | 5z i =
ng trn tm (2,-3) bn knh bng 5.
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0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Tm tt c cc s phc z t ha
| | | | 4z i z i + + =
23
| | | | 4 + + =z i z i
Tp hp tt ccc im trong mt phng sao cho tngkhong cch t n hai im cho trc (0,1) v (0,-1)khng thay i bng 4 chnh l ellipse.
0.2 Dng lng gic ca sphc
----------------------------------------------------------------------------nh ngha argument ca s phc
Gc c gi l argument ca s phcz vc k hiu larg( ) .=z
Gc c gii hn trong khongLu .
24
0 2 < hoc <
Cng thc tm argument ca s phc.
2 2
2 2
cos
sin
= =
+ = = +
a a
r a b
b b
r a b
hoc tg = b
a
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0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
GiiMun:
V d
Tm dng lng gic ca s phc 1 3.= +z i
1; 3.= =a b 2 2| | 2.= = + =r z a b
25
1 1os =
23 1
= =
+
ac
r
3 3sin =
23 1 = =
+
b
r
Suy ra2
3
=
Dng lng gic:
Argument:
2 21 3 2(cos sin )3 3
= + = +z i i
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Tm tt c cc s phc z t ha
| 2 | | 2 |z z = +
26
| 2 | | 2 | = +z z
Tp hp tt c ccim trong mt phng sao cho khong
cch t n haiim (2,0) v (-2,0) bng nhau.
y chnh l trc tung.
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0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
Gii
V d
Tm argument ca s phc 3 .= +z i
3; 1= =a b . Ta tm gc tha:
27
3 3os =
23 1 = =
+
ac
r
1 1sin =
23 1 = =
+
b
r
Suy ra6
=
Vy arg(z) =6
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
2 2; 0= + + >z a bi a b
2 2
2 2 2 2( )= + +
+ +
a bz a b i
a b a b
28
cos s n = +z r
Dng lng gic ca s phc(cos sin )z r i = +
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0.2 Dng lng gic ca sphc-----------------------------------------------------------------------------------------------------
1 1 1 1 2 2 2 2(cos sin ); (cos sin )z r i z r i = + = +
S bng nhau gia hai s phcdng lng gic
1 2
1 2 1 2 2
r rz z
k
==
= +
29
1 2 1 2 1 2 1 2(cos( ) sin( ))z z r r i = + + +
Nhn hai s phc dng lng gic: mun nhn vi nhau v
argument cng li.
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
Gii
V d
Tm dng lng gic, mun v argument ca s phc
(1 )(1 3).= + z i i
30
=
Dng lng gic:
2( os in ) 2( os in )4 4 3 3
= + +z c is c is
2 2[ os( ) in( )]4 3 4 3
= + + +z c is
2 2( os in ).12 12
= +z c is
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0.2 Dng lng gic ca sphc-----------------------------------------------------------------------------------------------------
Php chia hai s phcdng lng gic1 1 cos sin
z ri= +
1 1 1 1 2 2 2 2(cos sin ); (cos sin )z r i z r i = + = +
2 20 0. >z r
31
2 2z r
Chia hai s phc dng lng gic: mun chia cho nhau v
argument tr ra.
0.2 Dng lng gic ca sphc---------------------------------------------------------------------------------------------------------------------------
Gii
V d
Tm dng lng gic, mun v argument ca s phc
2 12.
3
=
+
iz
i
- -
32
2 2 33
= +
izi
Dng lng gic:7 7
2( os in ).6 6
= +z c is
cos s n
3 35 5
2(cos sin )6 6
+
=
+ i
- 5 - 52[cos( - ) sin( - )]
3 6 3 6
= +z i
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0.3 Dng mca sphc---------------------------------------------------------------------------------------------------------------------------
cos sini
e i
= +
nh l Euler (1707-1783)
33
z a bi= +
(cos sin )z r i = +
iz re
=
Dngi s ca s phc z
Dng lng gic ca s phc z
Dng m ca s phc z
0.3 Dng mca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Tm dng m ca s phc sau
3= +z i
34
Dng lng gic: 2(cos sin )6 6z i= +
Dng m:5
62 i
z e
=
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0.3 Nng sphc ln ly tha-----------------------------------------------------------------------------------------------------
V d. C h o z = 2 + i . T n h z5.
=+= 55 )2( iz
35
=++++++= 555555 22222 iCiCiCiCiCC
=+++++= iii 1.2.5).(4.10)1.(8.10.16.532
i4138 +=
0.3 Dng mca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Biu din cc s phc sau ln mt phng phc
2 ;i
z e R
+
=
36
Mun khng thayi, suy ra tp hp ccim lng trn.
2(cos sin )z e i = +
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0.3 Dng mca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Biu din cc s phc sau ln mt phng phc
3;a iz e a R
+=
37
(cos3 sin3)az e i= +
Argument khng thay i, suy ra tp hp cc im l nangthng nm trong gc phn t th 2.
0.4 Nng sphc ln ly tha
-----------------------------------------------------------------------------------------------------
nh ngha php nng s phc ln ly tha bc n
z a bi= +
2 2 2( )( ) ( ) (2 )z z z a bi a bi a b ab i= = + + = +
38
3 3 3 2 2 3
( ) 3 3 ( ) ( ) ...= + = + + + =z a bi a a bi a bi bi0 1 1 2 2 2( ) ( ) ( ) ... ( )n n n n n n nn n n nz a bi C a C a bi C a bi C bi
= + = + + + +
nz A iB= +
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0.3 Nng s phc ln ly tha--------------------------------------------------------------
Ly tha bc n ca s phc i:
ii =1
12 =i
23
iiiii === 145
1)1(1246
=== iii
iiiii === 1347
39
===
1)1()1(224 === iii 111448
=== iii
Ly tha bc n ca i
Gi sn l s t nhin, khiin = ir, virl phn d ca n chiacho 4.
0.3 Dng mca sphc---------------------------------------------------------------------------------------------------------------------------
V d
Tnh 1987
=z i
40
1987 4 496 3= +
1987z i=
4 496 3 3i i i
+= = =
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0.3 Nng sphc ln ly tha-----------------------------------------------------------------------------------------------------
Cho z = 1 + i.
a) Tm z3;
b) Tm z100.
V d
41
3 3) (1 )a z i= + 2 31 3 3i i i= + + +
1 3 3i i= +
2 2z i= +
) Tnh tng t rat phc tap. Ta s dung cach khacb
0.3 Nng sphc ln ly tha-----------------------------------------------------------------------------------------------------
z a bi= + (cos sin )r i = +
2 2(cos2 sin2 )z z z r i = = +
3 2 3(cos3 sin3 )z z z r i = = +
1n n n= =
42
[ (cos sin )] (cos sin )n nr i r n i n + = +
Cng thc De MoivreCho r > 0, cho n l s t nhin. Khi
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0.3 Nng sphc ln ly tha-----------------------------------------------------------------------------------------------------
V d. S dng cng thc de Moivres, tnh:
a) (1 + i)25 200)31( i+b)
20
17
)212()3(i
i+c)
43
Gii. a) Bc 1. Vit 1 + idng lng gic
)4
sin4
(cos21
iiz +=+=
Bc 2 . S dng cng thc de Moivres:
)4
25sin
4
25(cos)2()]
4sin
4(cos2[ 252525
iiz +=+=
Bc 3. n gin )4
sin4
(cos221225
iz +=
0.4 Khai cn sphc-----------------------------------------------------------------------------------------------------
nh ngha cn bc n ca s phc
Cn bc n ca sphc z l sphc w, sao cho wn =z, trong n l stnhin.
= =
44
2 2(cos sin ) (cos sin )n nn kk kz r i z r i
n n
+ += + = = +
vi k = 0, 1, 2, , n 1.
Cn bc n ca sphc z c ng n nghim phn bit.
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0.4 Khai cn sphc-----------------------------------------------------------------------------------------------------
V d. Tm cn bc n ca cc sphc sau. Biu din cc nghim lntrn mt phng phc.
3 8a) 4 3 + ib) 8
16
1
i
i+c)
6 1
3
i
i
+
d) 5 12i+e) 1 2i+f)
45
Gii cu a)
Vit sphc dng lng gic: 8 8(cos0 sin0)i= +
Sdng cng thc:
3 0 2 0 2
8(cos0 sin 0) 2(cos sin )3 3k
k ki z i
+ ++ = = +
0,1,2.k =
0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
nh l c bn ca i s cho bit c s nghim ca phngtrnh m khng ch cch tm cc nghim nh th no.
Nua thc vi h s thc, chng ta c mt h qu rt quan trng
46
H qu
Nua + bi l mt nghim phc caa thcP(z) vi h s thc, tha bi cng l mt nghim phc.
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0.4 Khai cn sphc-----------------------------------------------------------------------------------------------------
Gii cu b)
Vit sphc dng lng gic:
Sdng cng thc:
442 26 62(cos sin ) 2(cos sin )
6 6 4 4
+ ++ = = +k
k ki z i
3 2(cos sin )6 6
+ = +i i
47
, , , .=
0z
1z
2z
3z
0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
Nh bc hc ngi c Carl Friedrich Gauss (1777-1855) chngminh rng mia thc c t nht mt nghim.
48
nh l cbn cai sa thcP(z) bc n cng n nghim k c nghim bi.
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0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
(s dng h qu canh l cbn)
1) Tm a thc bc 3 vi hsthc nhnz1= 3i vz2= 2+i
V d
lm nghim.2) Tma thc bc 4 vi h s thc nhnz1= 3i vz2= 2+i
49
.
1) Khng tn ti a thc tha yu cu bi ton.
2)a thc cn tm l:
1 1 2 2( ) ( )( )( )( )P z z z z z z z z z=
( ) ( 3 )( 3 )( (2 ))( (2 ))P z z i z i z i z i= + + 2 2( ) ( 9)( 4 5)P z z z z= + +
0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
V d. Gii cc phng trnh sau trong C.
015 =+ iza)
0122 =++ izzd)
0224 =++ zzc)
012 =++ zzb)
50
Gii. Gii phng trnh 02 =++ cbzaz
acb 42 =Bc 1. Tnh
Bc 2. Tm2,1
2 4 == acb
Bc 3. 1 21 2;2 2
b bz z
a a
+ += =
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0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
Gii. Bi va thc vi h s thc v2 + i l mt nghim, theo hqu ta c2 i cng l nghim.
(s dng h qu canh l cbn)
Tm tt ccc nghim cabit 2 + i l mt nghim.
V d
4536144)(234
++= zzzzzP
51
z c p n c n z + z - =
= z2 4z + 5
P(z) c th ghidng
P(z) = (z2 4z + 5)(z2 + 9)
z2 + 9 c hai nghim 3i v3i. Vy ta tmc c 4 nghimcaP(z) l2 + i, 2 i, 3i, -3i.
0.5 nh l cbn ca i s---------------------------------------------------------------------------------------------------------------------------
Gii phng trnh sau trong C.
9 0z i+ =
V d
52
9z i= 9z i = 9 cos sin
2 2z i
= +
2 22 2cos sin
9 9k
k k
z i
+ +
= +
0,1,...,8.k =
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Kt lun---------------------------------------------------------------------------------------------------------------
2. Dng Lng gic ca s phc)sin(cos irz +=
1. Dngi s ca s phcbiaz +=
53
3. Nng ln ly tha)sin(cos)]sin(cos[ ninrirz nnn +=+=
4. Cn bc n ca s phc
)2sin2(cos)sin(cosn
ki
n
krzirz nknn
++
+==+=
.1,...,3,2,1 = nk
Thc hin php ton
Bi tp 1
)2(
)32(5
2
ii
iz
+=
54
Vit s phc saudng lng gic.
Bi tp 2
)3)(1( iiz ++=
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Vit s phc saudngi s
Bi tp 3
5)32( iz =
Bi t 4
55
Tm tt c cc s phc z t ha
1|21| + iz
Cho |z| = 2. Chng t
Bi tp 5
6 8 13z i+ +
Bi t 6
56
Cho |z| = 1. Chng t
21 | 3 | 4z
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Tm s phc z t ha
Bi tp 7
2z z i = +
Bi t 8
57
Tm s phc z t ha2
1 12 6z i z+ + =
Cho z l mt s phc khc 0. Tm mun ca s phc sau
Bi tp 9
2008z i
z
58
Xcnh tp hp ccim trong mt phng phc biu din cc sphc z t ha mn
Bi tp 10
zk
z i=
vi k l s thc dng cho trc.
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Tm s phc z t ha mnng thi
Bi tp 11
11
z
z i
=
v
31
z i
z i
=
+
59
Tm s phc z t ha mn
Bi tp 12
4
1z i
z i
+ =
Tm phn thc v phno ca s phc
Bi tp 13
3 2
1
i iz
i i
+=
+
60
Gii phng trnh .
Bi tp 14
2 | | 0z z+ =
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Vit dng lng gic ca mi s phc
Bi tp 15
2) sin 2sin
2
a i
+ ) cos (1 sin )b i + +
61
Tm s cn bc hai ca s phcz = - 8 + 6i.
Bi tp 16
Vit s phc saudngi s
Bi tp 17
5)32( iz =
62
Tm tt c cc s phc z t ha
1|21| + iz
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Xcnh phn thc ca s phc
Bi tp 19
1
1
z
z
+
bit rng |z| = 1 v 1.z
63
Chng minh rng nu l mt s o th |z| = 1.
Bi tp 20
1
1
z
z
+
Bi tp 21
Tnh v5cos 5sin
Tnh vncos nsin
64
Bi tp 22
Tnh , vi31
1
i
iz
+
=6 z
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Bi tp 23
Tnh , vi 16=z4 z
Bi tp 24
65
Tnh 3 22 i+
Bi tp 25
Tnh i41 +
Bi t 26
66
Gii phng trnh 07
=+iz
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Bi tp 27
Gii phng trnh 012 =++ izz
Bi tp 28
67
Chng t rng s phc 2 + 3 i l mt nghim ca phng trnh
05216174 234 =++ zzzz
v tm tt c cc nghim cn li.
Bi tp 29
Gii phng trnh
02)22()2( 23 =+++ iziziz
bit rng phng trnh c mt nghim thuno.
68
Bi tp 30
Phn tch x3 + 27 ra tha s bc nht v bc hai.
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Bi tp 31
Tnh 0 2 4 2006 2008
2008 2008 2008 2008 2008A C C C C C = + +
Bi tp 32Tnh
nA cos3cos2coscos ++++=
69
Bi tp 33
Tnh
cos cos( ) cos( ) cos( )A b b b b n = + + + + + + + +2
Vit dng lng gic ca mi s phc
Bi tp 34
2) sin 2sin2
a i
+ ) cos (1 sin )b i + +
70
Tm s phc z sao cho|z| = |z 2| v mt argument ca z 2 bng
Bi tp 35
mt argument ca z + 2 cng vi .2
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Chng minh rng nu b a s phc tha mn
Bi tp 36
th mt trong ba s phi bng 1.
1 2 3, ,z z z
1 2 3
1 2 3
| | | | | |
1
z z z
z z z
= =
+ + =
71
Xcnh tp hp ccim trong mt phng phc biu din cc s
Bi tp 37
2
2
z
z
+phc z sao cho c mt argument bng .3
72
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Trng i hc Bch khoa tp HCh MinhBmn Ton ng dng
-------------------------------------------------------------------------------------
Chng 1: Ma tran
Giang vien: Ts. ang Van Vinh (9/2008)
www.tanbachkhoa.edu.vn
NOI DUNG---------------------------------------------------------------------------------------------------------------------------
I. nh ngha ma tran va v du
II. Cac phep bien oi s cap
III. Cac phep toan oi vi ma tran
IV. Hang cua ma tran
V. Ma tran nghch ao
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I. Cc khi nim cbn v v d.---------------------------------------------------------------------------------------------------------------
nh ngham at rn
Ma trn c mxn l bng s (thc hoc phc) hnh ch nht c mhng v n ct .
Ma trn A cmxnCt j
=
mnmjm
iniji
nj
aaa
aaa
aaa
A
......
......
......
1
1
1111
Hng i
I. Cc khi nim cbn v v d.---------------------------------------------------------------------------------------------------------------
V d1.
32502
143
=A
y l ma trn thc c2x3.
Ma trn A c 2 hng v 3 ct.5;0;2;1;4;3 232221131211 ====== aaaaaaPhn tca A:
V d2
223
21
+=
ii
iA
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Tp hp tt ccc ma trn cmxn trn trng K c k hiul Mmxn[K]
Ma trn A c m hng v n ct thng c k hiu bi
nmijaA
=
I. Cc khi nim cbn v v d.---------------------------------------------------------
Ma trn c tt c cc phn t l khngc gi l ma trn khng,k hiu 0, (aij = 0 vi mi i v j ) .
nh ngha ma trn khng
=
000
000A
I. Cac khai niem c ban va v du---------------------------------------------------------------------------------------------------------------------------
Phn t khc khng u tin ca mt hng k t bn tric gi l phn t csca hng.
nh ngha ma trn dng bc thang1. Hng khng c phn tcs(nu tn ti) th nm di cng
2. Phn tcsca hng di nm bn phi (khng cngct) so vi phn tcsca hng trn.
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I. Cc khi nim cbn v v d.---------------------------------------------------------------------------------------------------------------------------
V d
52140
62700
23012
=A Khng l ma trnbc thang
=
5000
3000
2112
B Khng l ma trnbc thang
54
I. Cc khi nim v v dcbn.---------------------------------------------------------------------------------------------------------------------------
V d
52000
41700
22031
=A
L ma trn dng bcthang
L ma trn dngbc thang
54
=
7000
3100
2021
B
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I. Cc khi nim cbn v v d----------------------------------------------------------
Chuyn vca l ma trn cnXmthu c tA bng cch chuyn hng thnh ct.
( )mnij
TaA
=
nh ngha ma trn chuyn v
nmijaA
=
2393
01
42
=T
A32
904
312
=A
I. Cc khi nim cbn v v d.----------------------------------------------------------
Nu s hng v ct ca ma trn A bng nhau v bng n, th Ac gi l m a t rn vung cp n.
nh ngha ma trn vung
23
12
=A
Tp hp cc ma trn vung cp n trn trng s Kc k hiubi [K]nM
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I. Cc khi nim cbn v v d.----------------------------------------------------------
Cc phn t a11, a22,,ann to nnng cho chnh ca ma trnvung A.
2 3 1 1
3 4 0 5
2 1 3 7
2 1 6 8
I. Cc khi nim cbn v v d.----------------------------------------------------------
Ma trn vung c gi l m a t rn tam gic trn nunh ngha ma trn tam gic trn
=
200
630
312
A
( )ij n nA a =ij 0,a i j= >
Ma trn vung c gi l ma trn tam gic dinu
nh ngha ma trn tam gic di
2 0 0
4 1 0
5 7 2
A
=
( )ij n nA a =ij 0,=
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I. Cc khi nim cbn v v d.---------------------------------------------------------------
Ma trn vung Ac gi l ma trn cho nu cc phn t nmngoing chou bng khng, c ngha l ( aij = 0 , ij).
nh ngha ma trn cho
= 030
002
D
200
Ma trn cho vi cc phn t ng chou bng 1c gi lma trnn v, tc l ( aij = 0 , ij; v aii = 1 vi mi i).
nh ngha ma trn n v
=
100
010
001
I
I. Cc khi nim cbn v v d.---------------------------------------------------------------
Ma trn ba ng cho l ma trn cc phn t nm ngoi bang cho (ng cho chnh, trn n mtng, di n mtng)u bng khng.
nh ngha ma trn ba ng cho.
=
9500
1840
0713A
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I. Cc khi nim cbn v v d.---------------------------------------------------------------
Ma trn vung thc A t ha aij = aji vi mi i = 1,.n v j =1,,nc gi l m a t rni xng (tc l , nu A = AT)
nh ngha ma trn i xng thc
= 741
312
A
Ma trn vung A tha aij = - aji vi mi i v j (tc l A = -AT)c gi l m a t rn phni xng.
nh ngha ma trn phn i xng
1 3
1 7
3 7
0
0
0
A
=
II. Cc php bin i scp.---------------------------------------------------------------------------------------------------------------------------
Cc php bini scpi vi hng
; 0 i ih h1. Nhn mt hng ty vi mt skhc khng
; + i i jh h h
2. Cng vo mt hng mt hng khcc nhn vi mt sty
i jh h3.i ch hai hng ty
Tng t c ba php bini scpi vi ct.
Ch : cc php bin i s cp l cc php bin i c bn,thng dng nht!!!
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II. Cc php bin i scp.---------------------------------------------------------------------------------------------------------------------------
Mi ma trn u c tha vma trn dng bc thang bng ccphp bin i scp i vi hng.
nh l 1
Khi dng cc php bin i scp i vi hng ta thu cnhiu ma trn bc thang khc nhau
Ch
II. Cc php bin i scp.---------------------------------------------------------------------------------------------------------------------------
Dng cc php bin i s cp i vi hng a ma trn sauy v ma trn dng bc thang.
1 1 1 2 1
2 3 1 4 5
3 2 3 7 4
1 1 2 3 1
V d
Bc 1. Bt u tct khc khng u tin tbn tri. Chnphn tkhc khng ty lm phn tcs.
1 1 1 2 1
2 3 1 4 5
3 2 3 7 4
1 1 2 3 1
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1 1 1 2 1
0 1 1 0 3
0 1 0 1 1
0 2 1 1 2
4 4 1 +
h h h
2 2 12 h h h
3 3 13 h h h
Bc 2. Dng bsc i vi hng, khtt ccc phn tcn li cact.
II. Cc php bin i scp.---------------------------------------------------------------------------------------------------------------------------
1 1 1 2 1
2 3 1 4 5
3 2 3 7 4
1 1 2 3 1
A
=
4 4 3
1 1 1 2 1
0 1 1 0 3
0 0 1 1 4
0 0 0 0 0
+
h h h
Bc . Che tt ccc hng thng cha phn tcsv nhnghng trn n. p dng bc 1 v 2 cho ma trn cn li
3 3 2
4 4 22
1 1 1 2 1
0 1 1 0 30 0 1 1 4
0 0 1 1 4
+
h h hh h h
II. Cc php bin i scp.---------------------------------------------------------------------------------------------------------------------------
Nu dng cc bin i scp a A vma trn bc thangU, th U c gi l dng bc thang ca A.
nh ngha
Ct ca ma trn bc thang A c gi l ct csnu ct
nh ngha
c a p n cs
1 2 0 2
0 0 1 3
0 0 0 7
A
=
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------------------
Hai ma trn bng nhau nu: 1) cng c; 2) cc phn t nhngv tr tngng bng nhau (aij = bij vi mi i v j ) .
Sbng nhau ca hai ma trn
Php cng hai ma trn
Tng A + B :Cng c
Cc phn t tngng cng li
=
=
741
623;
503
421BA
=+
1244
1002BA
V d
III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------------------
Php nhn ma trn vi mt s.Nhn ma trn vi mt s, t a ly s nhn vi tt c cc phn
t cam at rn.
=503
421A
=842
2 A
V d
Tnh cht:a) A + B = B + A; b) (A + B) + C = A + ( B + C);
c) A + 0 = A; d) k(A + B) = kA + kB;
e) k (mA) = (km) A; f) (k + m)A = kA + mA;
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------------------
Php nhn hai ma trn vi nhau
( ) ; ( )pij m i pj nA a B b = =
nmijcCAB == )( vi pjipjijiij bababac +++= ...2211
1*
* *
jb
b
tm phn tc2,3ma trn tch: ly hng 2 ca A nhn vi ct 3ca B (coi nhnhn tch v hng hai vctvi nhau)
1 2 ... ... ...
*
i i ip
pj
ijAB a a a
b
c= =
11 12 13
1 2 22 1 4 c c c
III. Cc php ton i vi ma trn---------------------------------------------------
=
=
342
103
221
;014
412BA
V d
Tnh AB
12 137 c c
21 22 234 1 0 2 4 3 c c c
11c = ( )2 1 4
1
3
2
2 1 ( 1) 3 4 2 7= + + =
21 22 23c c c
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------
2 1 1;
4 1 3
= =
A B
V d
Tm ma trnX
, thaAX = B
.
a
.
AX=B
b
2 1 1
4 1 3
a
b
=
2 1
4 3
a b
a b
=
+
2 1
4 3
a b
a b
=
+ =
2 1,
3 3a b = =
2 / 3Vay
1/ 3X
=
III. Cc php ton i vi ma trn---------------------------------------------------
a. A(BC) = (AB)C; b. A(B + C) = AB + AC;
e. k (AB) = (kA)B = A(kB).
d. ImA = A = A Im
Tnh cht ca php nhn hai ma trn
c. (B + C)A = BA + CA;
Ch :1. Ni chung BAAB
2. ACAB = CB =
0=AB 00 == BA3.
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------------------
Nng ma trn ln ly tha.
nA A A A A=
0Qui c: A I= 2A A A=
3A A A A=
nnijn
nn
n aAaxaxaxaxf
=++++= )(;...)( 011
1
n
11 1 0( ) ... .
n nn nA a A a A a IA a
= + + + +
III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------
22 1 ; ( ) 2 4 33 4
A f x x x
= = +
V d
Tnh f(A).
2( ) 2 4 3A A IA= +
2 1 2 1 2 1 1 0( ) 2 4 33 4 3 4 3 4 0 1
A
= +
1 6 8 4 3 0( ) 2
18 13 12 16 0 3A
= +
3 8( )
24 13
A
=
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------
1 3.
0 1A
=
V d
Tnh A2; A3, t suyraA200
2 1 3 1 3
1 6
0 1 0 1 10
3 2 1 6 1 3
0 1 0 1A A A
= =
1
1
9
0
=
200 1
0 1
200 3A
=
III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------
2 3.
0 2
=
A
V d
Tnh A200
2 3 1 3/ 2
1 a
0 2 0 1 0 1
1 1Ta co:
0 1 0 1
na na
=
200200200
200
3002 2
0 2A
=
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III. Cc php ton i vi ma trn---------------------------------------------------------------------------------------------------------------
1 1.
1 1
=
A
V d
Tnh A200
2 1 1 1 1 2 2 1 1
1 1 1 1 2 2 1 1
1Suy ra: A 2n n A=
199 199200
199 1992 2
2 2A =
3 2.
2 3
=
AV d
Tnh A200
1 1 1 02 2
1 1 0 1A B I
= + = +
V B v I giao hon nhau nn ta dng nhthc Newton
12n nB B=
( ) ( ) ( )200 200 1990 1 200 200200 200 2002 2 2 ...B I C B C B C I+ = + + +
0 200 200 1 1 199 199 1 200 200200 200 2002 .2 2 .2 ...C B C B C I
= + + +
( )0 200 1 199 199 200200 200 200 2004 4 ... .42
BC C C C I = + + + +
( )( )200
4 1 1 . 2
B
I= + +
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IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
nh ngha hng ca ma trn
Gi s Amxn tngng hng (ct) vi ma trn bc thangE. Khi ta gi hng ca ma trn A l s cc hng khc
r(A) = s hng khc khng ca m a t rn bc thang E
IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
V dTm hng ca m a t rn sau
1 2 1 1
2 4 2 2
3 6 3 4
A
=
Gii. 1 2 1 1
2 4 2 2
3 6 3 4
=
A
1 2 1 1
0 0 0 0
0 0 0 1
2 3
1 2 1 1
0 0 0 1
0 0 0 0
h h( ) 2r A =
2 2 1
3 3 1
2
3
h h h
h h h
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IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
V dS dng bini scp, tm hng cam at rn sau
1 2 3 3
2 4 6 9
2 6 7 6
A
=
V dTm hng ca m a t rn sau
2 3 1 4
3 4 2 9
2 0 1 3
A
=
IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
V dTm tt c cc gi tr thc m sao cho r(A) =3
1 1 1 2
2 3 4 1
3 2 1
=
+
A
m m
1 1 1 2 1 1 1 2
2 3 4 1 0 1 2 3
3 2 1 0 1 3 5
=
+
A
m m m m
1 1 1 2
0 1 2 3
0 0 1 8
m m
r(A) = 3 vi mi gi trm.
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IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
V dTm tt c cc gi tr thc m sao cho r(A) =2
1
11
m m
A m mm m
=
V dTm tt c cc gi tr thc ca m cho r(A) = 3.
1 1 1 1
2 3 1 4
3 3 1
A
m m
=
+
IV. Hng ca ma trn-----------------------------------------------------------------------------------------------------
Tnh cht ca hng ma trn
1. r (A) = 0 A = 0
2. A = (aij)mxn r(A) min{m, n}
BSC3. Nu A B, th r (B) = r (A)
2 2 2
2 2 2
2 2 2
A
=
2 2 2
0 0 0
0 0 0
( ) 1.r A =
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V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
nh ngha m a t rn nghcho
Ma trn vungAc gi l ma trn kh nghch nu tn tima trnIsao cho AB = I =BA. KhiBc gi l nghcho caA v k hiu lA-1.
2 1 3 1 2 2
5 3
=
2 25 2
2 1 3 1 1 0
5 3 5 2 0 1AB I
= = =
3 1 2 1 1 0
5 2 5 3 0 1BA I
= = =
1 3 1
5 2A B
= =
V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Khng phi bt kma trn vungA no cng khnghch. Crt nhiu ma trn vung khng khnghch.
Ch
Ma trn khnghch c gi l ma trn khng suy bin
n ng a
Ma trn khng khnghch c gi l ma trn suy bin
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V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Cho ma trn vung A, cc mnh sau y tng ng
Stn ti ca ma trn khnghch.
1. Tn tiA-1 (A khng suy bin)
.
3. AX = 0 suy raX = 0.
4. A ITng ng hng
V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Ma trn thu c tI bng ng 1 php bin i scp cgi l ma trn scp.
nh ngha ma trn scp
V d1 0 0 1 0 0
2 2 12
2
1 0 0 1 0 0
0 1 0 2 1 0
0 0 1 0 0 1
h h hI E
+
= =
3 33
10 1 0 0 1 00 0 1 0 0 3
h h
I E
= =
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V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Mt php bin i scp i vi hng ca ma trn A ng
3 1
3
1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
h hI E
= =
ngha vi nhn bn tri A vi ma trn sc p tng ng.
Mt php bin i scp i vi ct ca ma trn A ng
ngha vi nhn bn phi A vi ma trn scp tng ng.
V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
3 1
2 1 1 3 2 1
1 1 0 1 1 0
3 2 1 2 1 1
h hA B
= =
3 2 1 0 0 1 2 1 1
1 1 0 0 1 0 1 1 0
2 1 1 1 0 0 3 2 1
=
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V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
1 1bsc hang
...n nA I I E E E A =
11 1...n nA E E E I
=
1 trenbsc hangI A
V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Cch tm A-1
[ A|I ] [ I|A-1 ]Bsc i vi hng
V dTm nghcho (nu c ) cam at rn
=
111
321
=
101
011
001
210
110
111
100
010
001
321
221
111
]|[ IA
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V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
110
121
111
100
010
011
110
011
001
100
110
111
]|[
110
121
100
010 1=
AI
=
110
121
0121
A
V. Ma trn nghch o-----------------------------------------------------------------------------------------------------
Tnh bng cc php scp i vi hng ca ma trn[ A|I ] ta cn sdng
phc tp ca thut ton tm A-1
n3 php nhn hoc chia
n3 2n2 + n php cng hoc tr
1
nnA
i vi hai ma trn khnghch A v B, cc khng nh sau yng.
Tnh ch t ca ma trn nghch o
(A-1)-1 = A
Tch AB l hai ma trn khnghch.
(AB)-1 = B-1A-1
(AT)-1 = (A-1)T
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IV. Ma trn nghch o-----------------------------------------------------------------------------------------------------
V dTm tt c cc gi tr thc m ma trn sau kh nghch
1 1 2
2 13 2 1
=
A m
V dTm tt c cc gi tr thc ca m choAkh nghch.
1 1 1 1
2 3 1 4
3 3 1
A
m m
=
+
VI. Kt lun------------------------------------------------
Ma trn l g? Ma trn vung ? Ma trn bc thangMa trn khng? Ma trn cho? Ma trn chuyn v?
Ma trn n v? Ma trn i xng?
Cc php ton i vi ma trn: Sbng nhau Php cng
Nhn ma trn vi mt s Nhn hai ma trn vi nhau
Hng ca ma trn l g?
Lm thno tm hng ca mt ma trn cho trc?
Ma trn khnghch l g?
Lm thno tm nghch o ca mt ma trn cho trc?
Nghch o ca ma trn A l g?
Nng ln ly tha
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Thc hin php tonBi tp 1
2 3 21 2 1
1 2 33 0 4
Tm f(A), bit
Bi tp 2.
23 4 5x x x= + v 2 3
A
=
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Bi tp 3.
Tm ma trnX , saochoA X =B,vi2 1
=2
=3 1 3
Cho
Bi tp 4
2 12 3 4
; 1 31 2 7
3 2
A B
= =
3 2 T
A B+
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a m a t rn s a u v dng bc thang bng bini scp
Bi tp 5.
1 1 2 1 1
2 1 3 4 2
3 4 7 3 1
1 3 4 7 3
Bi tp 6Tm ma trn nghcho, nu c 1 1 1
2 3 1
3 4 1
A
=
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Bi tp 7a v ma trn bc thang, tm hng cam at rn
1 1 1 0
2 0 1 3
Bi tp 8
Tm ma trn A , nu
1 0 5 25 3A A
=
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Bi tp 9
Tm cc gi tr ca s v t, sao cho ma trn sau li xng
2s s st
2t s s
Bi tp 10
Cho , cho A l ma trn c3xn , B cnx3.1 0 0
0 0 1P
=
a )Mt PA theo ngha bini scpi vi hngb)Mt BP theo ngha bini scpi vi ct
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Bi tp 11
Cho A, B, C l cc ma trn,n gin biu thc sau
Bi tp 12
Tm ma trn nghcho ca A
2 7 1
1 4 1A
=
1 3 0
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Bi tp 13
Tnh A43, bit
2 1 =
3 2
Cho l ma trn vung.
Bi tp 14
cos sin
sin cosA
=
a) Tnh A2.
b) Tnh An.
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Bi tp 15
Cho hai ma trn A v B
1 1 1
3 2
=
0 0 2
= 0 1
Tm tt c ma trn X, sao cho AX = B.
Bi tp 16
Tm tt c cc gi tr msaocho(A)=2
1 1
1 1
m
A m
=
1 1 m
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Bi tp 17
Bin lun t h e o m hng ca m a t rn A
1 1 2
2 1 5
m
A m
=
1 10 6 m
Bi tp 18
Tm tt c s thc m, sao cho ma trn A k h nghch
1 1 1
2 3 1A
=
3 5 m
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Bi tp 19
Tm tt c cc s thc m, sao cho ma trn A k h nghch
1 1 1 2
2 3 1 4A
=
3 2 1m m +
Bi tp 20
Gi s A l ma trn kh nghch cp 5. Tm r(A) v r (A-1)
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Trng i hc Bch khoa tp. HCh MinhBmn Ton ng dng
---------------------------------------------------------------
i stuyn tnh
Chng 2: nh thc
Ging vin Ts. ng Vn Vinh (9/2008)
www.tanbachkhoa.edu.vn
NI DUNG---------------------------------------------------------------------------------------------------------------------------
I nh nghanh thc v v d.
II Tnh cht canh thc
III Khai trin Laplace
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I. nh ngha v v d---------------------------------------------------------------------
Cho l ma trn vung cp n.
nh thc ca A l mt sk hiu bi detnnij
aA
=
AaAnnij
==
)(
K hiu lnh thc thuc tA b n cch b i hnMthi v ct th j ca ma trn A;
ij( 1)i j
ijA M+
= Bi sca phn taij li lng
nh ngha bi sca phn taij
I. nh ngha v v d---------------------------------------------------------------------------------------------------------------------------
b) k =2: 11 12
11 22 12 21 11 11 12 1221 22
a aA A a a a a a A a A
a a
= = = +
a) k =1: [ ] 1111 aAaA ==
nh nghanh thc bng qui np
c) k =3:
11 12 13
21 22 23 11 11 12 12 13 13
31 32 33
a a a
A a a a A a A a A a A
a a a
= = + +
d) k =n: 11 12 1
11 11 12 12 1 1*
nn n
a a aA A a A a A a A
= = + + +
...............
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I. nh ngha v v d---------------------------------------------------------------------------------------------------------------------------
1 2 3A A A A= + +
Tnh det (A), vi
=
423
032
321
A
V d
Gii
23
32)1()3(
43
02)1(2
42
03)1(1
312111 +++++=A
11151612 =+=A
1 1 1 111
1 2 33 0
2 3 0 ( 1) 122 4
3
( )
2 4
1A + +
== =
II. Tnh cht ca nh thc---------------------------------------------------------------------
1. C th tnh nh thc bng cch khai trin theo bt khng hoc ct ty no
*
a a a a A a A a A= = + + +
1
2
1 1 2 2
* *
j
j
j j j j nj nj
nj
a
aa A a A a A
a
= = + + +
*
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Tnhnh thc det (A), vi
=
004
225
313
A
V d
Khai trin theo hng th3
322231)1(4
004
225
313
)1(4
004
225
3131313
==
=
= ++
A
Gii.
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
2 3 3 2
3 0 1 4
V d
n n c e , v
2 0 3 2
4 0 1 5
=
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Khai trin theo ct thhai
12 22 32 42 12
2 3 3 23 0 1 4
( 3) 0 0 0 3A A A A A A
= = + + + =
Gii
4 0 1 5
3 1 4
3 2 3 2 87
4 1 5
A = = =
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
nh thc ca ma trn tam gic bng tch cc phn t nmtrnng cho.
V d
120145)3(2
10000
94000
82500
1763040312
==
=A
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Sdng bini scpi vi hngtnhnh thc
1.Nu thi ih hA B
| | | |B A=
i i jh h h + | | | |B A=
3. Nu thi jh h
A B
| | | |B A=
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
V d
Sdng cc php bini scp, tnhnh thc
0532
1211
=
13122623
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17301010
2110
1211
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Gii
1312
2623
0532
1211
||
=A
2 2 12 h h h
3 3 13 h h h
4 4 12 +h h h
1504101
211
||
=A
Khai trin theo ctu tin||A
173
101
211
)1(1 11
+
19154
11
)1(1 21
=
=
+
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Bc 1. Chn 1 hng (hoc mt ct) ty ;
Bc 2. Chn mt phn tkhc khng ty ca hng (hay ct)bc 1. Dng bini scp, khtt ccc phn tkhc.
Nguyn tc tnhnh thc sdng bini scp
Bc 3. Khai trin theo hng (hay ct) chn.
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
V d
Sdng bini scp, tnhnh thc
=02321123
A
1314
2413
0411
0253
0232
1123
1314
2413
0232
1123
||
=A
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Gii
3 3 12 +h h h
4 4 1 h h h
2 3 2
| | 5 8 0
5 5 0
A
=
411
253232
)1(1 41
+
1 35 8( 2) ( 1) 30
5 5
+= =
Khai trin theo ct s4||A
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
det (AT) = det (A)
det(AB) = det(A) det(B)
Ma trn c mt hng (ct) b ng khng, th det (A) = 0
Ma trn c hai hng (ct) tlnhau, th det (A) = 0
Ch :det(A+B) det(A) + det(B).
II. Tnh ch t ca nh thc---------------------------------------------------------------------------------------------------------------------------
GisAl ma trn khnghch nxn. Khi tn ti matrn khnghch A-1, sao cho AA-1 = I. Suy ra
Chng minh
Ma trn vungA khnghchkhi v chkhi det(A) 0.
nh l
det(AA-1) = det (I) det(A).det(A-1) = 1 det(A) 0
1 1AA P
A
= , vi
11 12 1
21 22 2
1 2
Tn
nA
n n nn
A A A
A A AP
A A A
=
Gisdet(A) 0. Khi
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
| |A i =
=
*
*
*
111
111
iii
jjj
aaa
aaa
A
=
*
*
*
111
111
jjj
jjj
aaa
aaa
B
1 1 2 20,
i j i j in jna A a A a Ai j
+ + + =
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Tnh cht ca ma trn nghcho
1. 1 1det( )
det( )A
A
=
1n=
Chng minh.
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
ChoA l ma trn khnghch. Khi
11 12 1T
nA A A
Cng thc tnh ma trn nghcho A-1
1 1AA P
A
= , vi 21 22 2
1 2
nA
n n nn
A A AP
A A A
=
II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
V d. Tm ma trn nghcho ca
=
043
132
111
A
Gii. 02)det( =A Akhnghch
Tnh 9 bi sca cc phn t
1 111 ( 1) 4;4 0A +
= = 1 212 ( 1) 3;3 0A +
= = 1 313 ( 1) 13 4A +
= =
21 22 23 31 32 334; 3; 1; 2; 1; 1A A A A A A= = = = = =
1
4 4 21
3 3 12
1 1 1
A
=
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Tnh det(A), nu
V d1
2 1 1 3
3 2 1 2
4 1 0 1
3 3 2 2
=
Tnh det(A), vi
V d2
4 1 1 0
3 2 4 1
2 1 3 1
5 1 2 3
=
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Khngnh no sauyng?
V d3
2
3
2 1 3
3 2 3 1( )
3 5 2 1
6 3 2 1 9
x
xf x
x x
x
+=
+
+
a) Bc ca f(x)l 5.
b) Bc ca f(x)l 4.
c) Bc caf(x)l 3.
d) Cc cu khcu sai.
Tnhnh thc ca ma trn sau
V d4
1 0 1 i+
0 11 1
A ii i
=
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Tnhnh thc
V d5
1 2 2 2 2
2 1 2 2 2
2 2 1 2 2
2 2 2 1 2
2 2 2 2 1
I =
Gii phng trnh, vi a, b, c l cc sthc.
V d6
2 3
2 3
1
1
x x x
a a a
2 3
2 3
1
1
b b b
c c c
=
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Gii phng trnh
V d7
1 1 1 11 1 1 1x
1 1 1
x
n x
=
Tnhnh thc
V d8
1 1 1 1
1 0 1 1
1 1 0 1
1 1 1 0
I =
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Tnhnh thc
V d9
1 2 3 n
1 2 0 0
1 2 3 0
nD
=
Tnhnh thc
V d10
3 2 2 2
2 2 3 2
2 2 2 3
nD =
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Gii phng trnh trong C
V d11
2 2 3x
0
0 0 7 6
0 0 5 3
=
Tnhnh thc
V d12
7 5 0 0
0 2 7 0
0 0 0 7
nD =
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Khai trin theo hng 1, ta cGii v d9 11 127 5nD A A= +
1 1 1 1
7 5 0 0 2 5 0 0
2 7 5 0 0 7 5 0
7( 1) 5( 1)0 2 7 0 0 2 7 0
0 0 0 7 0 0 0 7
nD + +
= +
1 11
7 5 0 0
2 7 5 0
7 5.2( 1) 0 2 7 0
0 0 0 7
n nD D +
=
1 2
7 10n n n
D D D
=
1 1 25 2( 5 )n n n nD D D D =
1 2 2 35 2( 5 )n n n nD D D D =
21 2 35 2 ( 5 )n n n nD D D D =
21 2 15 2 ( 5 ) *( )
nn nD D D D
=
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1 27 10n n nD D D =
1 1 22 5( 2 )n n n nD D D D =
1 2 2 32 5( 2 )n n n nD D D D =
1 2 12 5 ( 2 ) * )*(n
n nD D D D
=
21 2 15 2 ( 5 ) *( )
nn nD D D D
=
1 2* **( ) & ( ) theo vanD D D
Tnhnh thc
V d13
5 3 0 0
0 2 5 0
0 0 0 5
nD =
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Tnhnh thc
V d14
9 5 0 0
0 4 9 0
0 0 0 9
nD =
Tm ma trn nghcho bng cch tnhnh thc
V d15
1 2 1
2 3 1A
=
3 5 2
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Tm ma trn nghcho ca ma trn sau
V d16
1 0 0 0
2 1 0 0
5 4 1 0
1 2 3 2
=
Tm tt ccc gi trca mma trn sau khnghch
V d17
1 1 2 1
2 1 5 3A
=
5 0 7
1 2 3 3
m
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Tm tt ccc gi trthc ca mma trn sau khnghch.
V d18
1 2 1 1 1 12 3 2 3 2A m
=
Cho . 1) Tnh det (A-1).
V d19
1 1 1
2 3 1
3 3 5
A
= 2) Tnh det (5A)-1.
3) Tnh det (PA).
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Cho
V d20
3 3[ ]; [ ];det( ) 2;det( ) 3.A M R B M R A B = =
1) Tnh det (4AB)-1.
2) Tnh det (PAB).
Cho k l s t nhin nh hn hoc bng n; i1, i2, , ikv j1, j2,, jkl nhng stnhin tha
1 ... ;1 ...i i i n j j j n < < < < < <
III. Khai trin Laplace
-----------------------------------------------------------------------------
nh thc con cp k, k hiu bi , lnh thc thuc tA bi nhng phn tgiao ca k hng i1, i2, , ikv k ct j1, j2, , jk.
1
1
,...,
,...,k
k
i i
j ja
nh nghanh thc con cpk
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III. Khai trin Laplace
-----------------------------------------------------------------------------
i lng 1 111
1
1
. . . . . . ,, . . . ,
,
. . . ,
. . . , , . . . ,( 1 )n
n
n n n
n
i ii i
j j
j j i i
j jMA + + + + +
=
c gi l bi scpkca 11
,...,
,...,k
k
i i
j ja
nh l (Khai tri n Laplace)nh thc ca ma trn vung A bngtng tt c cc tchcanhthc con cp krt ra t k hng (hoc k ct) no vi bi sca chng.
III. Khai trin Laplace
-----------------------------------------------------------------------------
Tnhnh thc bng khai trin Laplace.
bc 1. Chn k hng (hoc k ct) ty
bc 2. Tnh tt c ccnh thc con cp k thuc t k hngchn. Tng cng c nh thc con cpk.k
nC
bc 3. Tm tt ccc bi scp k tngng ca ccnh thccon cpkbc 2.
bc 4.nh thc ca ma trn A bngtng tt ccc tch canhthc con cp k vi bi sca chng.
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III. Khai trin Laplace
-----------------------------------------------------------------------------
V d21
Tnhnh thc ca A bng cch sdng khai trin Laplace.
2 3 1 13 0 1 0
A
=
1 0 2 0
III. Khai trin Laplace
-----------------------------------------------------------------------------
Gii
Chn k = 2, chn 2 hng: hng 2 v hng 4.
3 0 1 0
1 0 2 0
T n t i nh thc con c 2 nhn chc 1 khc khn .2 =
2,41,3
3 15
1 2a
= =
2,4 2 4 1 31,3
3 1( 1) 1
2 1A
+ + += =
2,4 2,41,3 1,3det( ) . 5.1 5A a A= = =
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Tnh det(A) sdng khai trin Laplace
V d22
2 1 2 3 5
1 0 3 0 2
3 4 2 5 1
2 0 1 0 4
3 2 5 2 1
A =
III. Khai trin Laplace
----------------------------------------------------------------------------
Chn k = 2, chn 2 hng: hng 2 v hng 4.1 0 3 0 2
2 0 1 0 4
Tn ti nh thc con cp 2 nhng chc 2 khc khng.25 10C =
2,41 3
1 35a = = 2,4 1 3 2 4
1 3 5+ + +
1,3
2 2 1
2,4 2,4 2,4 2,4 2,4 2,41,3 1,3 1,5 1,5 3,5 3,5det( ) . . .A a A a A a A= + +
2,41,5
1 20
2 4a = =
2,43,5
3 210
1 4a = =
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II. Tnh cht ca nh thc---------------------------------------------------------------------------------------------------------------------------
Tnhnh thc bng bi scn n! php ton.
Nu mt my tnh siu tc c th tnh t t php tontrong mt giy thtnh mtnh thc cp 25 cn 500.000nm (cn 25! , khong 1.5x1025 php ton).
Phn ln cc my tnh s dng bin i s cp tnhdet (A).
Cc php bin i s cp cn (n3+2n-3)/3 php nhn v
chia. Bt kmy tnh no cng c thtnhnh thc cp 25trong vng phn ca 1 giy, chcn khong 5300 php ton.
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Trng i hc Bch khoa tp. HCh MinhBmn Ton ng dng
---------------------------------------------------------------
i stuyn tnh
Chng 3: Hphng trnh tuyn tnh
Ging vin Ts. ng Vn Vinh (9/2007)
www.tanbachkhoa.edu.vn
Ni dung---------------------------------------------------------------------------------------------------------------------------
I H phng trnh tuyn tnh tng qut
II H hn trnh tu n tnh thu n nh t
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
11 1 12 2 1 1
21 1 22 2 2 2
n n
n n
a x a x a x ba x a x a x b
+ + + =
+ + + =
H phng trnh tuyn tnh gm m phng trnh, n n cdng:
nh ngha h phng trnh tuyn tnh.
a11, a12, , amnc gi l h s ca h phng trnh.
1 1 2 2m m mn m ma x a x a x b
+ + + =
b1, b2, , bmc gi l h s t do ca h phng trnh.
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
H phng trnh tuyn tnh c gi l thun nht nu tt ccc h s t do b1, b2, , bmu bng 0.
nh ngha h thun nht.
nh ngha h khng thun nht.
Nghim ca h l mt b n s c1, c2, , cm sao cho khi thayvo tng phng trnh ca h tac nhngng thcng.
p ng r n uy n n c g ng u n n n u
nht mt trong cc h s t do b1, b2, , bm khc 0.
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
H tng thch
H khng tng thch
Mt h phng trnh tuyn tnh c th:
1. v nghim,
2. c duy nht mt nghim3. C v s nghim
Hai h phng trnhc gi l tngng nu chng cngchung mt tp nghim.
gii h phng trnh ta dng cc php bini h vh tngng, m h ny giin gin hn.
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
C 3 php bini tngngi vi h phng trnh .
Mt php binic gi l tngng nu bin mt hphng trnh v mt h tngng.
nh ngha php bini tngng
1. Nhn hai v ca phng trnh vi mt s khc khng.
3.i ch hai phng trnh.
2. Cng vo mt phng trnh mt phng trnh khc c nhn vi mt s ty .
Ch : Chng ta c th kim tra d dng rng cc php bini trn l cc php bini tngng.
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
0y+ =
Gii h phng trnh:
0
2 3 3
2 3
x y
x y z
x y z
+ =
+ =
=
V d
1 2
1 3h h
+ 3 3 3
3 3
y z
y z
+ =
=
2 3h h +
0
3 3 3
4 0
x y
y z
z
+ =
+ = =
Phng trnh c nghim duy nht : x = 1 ; y = - 1 ; z = 0
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
1 1 0
2 1 3
1 2 1
Ma trn h s:
Ma trn mrng:1 1 0 02 1 3 3
1 2 1 3
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
1 1 0 0
2 1 3 3
1 2 1 3
1 1 0 0 1 2
1 3
2h h
h h
+
+
2 3h h +
0 3 3 3
0 3 1 3
1 1 0 0
0 3 3 3
0 0 4 0
I. Hphng trnh tuyn tnh tng qut
n csln tngng vi ct cha phn t cs.
n t d o l tngng vi ct khng c phn t cs.
nh nghan csvn t do.
1 1 1 2 12 2 3 5 6
3 3 4 1 1
BSC HNG1 1 1 2 10 0 1 1 4
0 0 0 6 8
x1, x3, x4: l cc n cs
x2: n tdo
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N u , th h AX = b v n him.( | ) ( )r A b r A
I. Hphng trnh tuyn tnh tng qut
nh l Kronecker Capelli
Nu hai ma trn m rng ca hai h phng trnh tuyn tnhtngng hng vi nhau th hai h tngng.
Nu , th h AX = b c nghim.( | ) ( )r A b r A=
Nu = s n, th h AX = b c nghim duynht.
( | ) ( )r A b r A=
Nu < s, th h A X = b c v s nghim.( | ) ( )r A b r A=
I. Hphng trnh tuyn tnh tng qut--------------------------------------------------------------------------------------------------
2. Dng bin i scp i vi hng a ma trn mrngvma trn dng bc thang. Kim tra hc nghim haykhng
Sdng bin i scp i vi hng gii h
1. Lp ra ma trn mrng ( | )A A b=
3. Vit hphng trnh tng ng vi ma trn bc thang
4. Gii hphng trnh ngc tdi ln, tm n xn, sau xn-1, ., x1.
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I. Hphng trnh tuyn tnh tng qut----------------------------------------------------------------------------------------------------------------------
Gii cc h phng trnh sau y vi cc ma trn m rng chotrc.
1 5 2 6 1 1 1 3
V d
. ,
0 0 5 0
a
. 0 1 2 4 ,
0 0 0 5
b
1 1 1 0
. 0 1 2 5 ,0 0 0 0
c
1 1 1 0
. 0 3 1 0 .
0 0 0 0
c
I. Hphng trnh tuyn tnh tng qut--------------------------------------------------------------------------------------------------------------------
V d
5 2 1
4 6
3 3 9
x y z
x y z
x
+ + =
+ =
+ =
Gii h phng trnh:
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
3
3 5 9 2
2 3 3
y z
x y z
x
+ =
+ + =
+ + =
V d
Gii h phng trnh
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
Tm nghim tng qut ca hphng trnhV d
2 3 4 5
1 2 3 4 5
1 2 3 4 5
3 6 6 4 5
3 7 8 5 8 9
3 9 12 9 6 15
x x x x
x x x x x
x x x x x
+ + =
+ + =
+ + =
n cs: 521 ,, xxx n tdo: 43 ,x
Nghim tng qut:
1
2
3
4
5
24 2 3
7 2 2
4
x
x
x
x
x
= +
= +
=
=
=
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I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
Tm nghim tng qut ca hphng trnh bit ma trn mrng
V d
1 1 1 1
2 3 4 1
3 4 2 1
I. Hphng trnh tuyn tnh tng qut-----------------------------------------------------------------------------------------------------------
---
Tm nghim tng qut ca hphng trnh bit ma trn mrng
V d
1 1 2 0
2 1 5 0
3 4 5 0
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I. Hphng trnh tuyn tnh tng qut-----------------------------------------------------------------------------------------------------------
--
Tm nghim tng qut ca hphng trnh bit ma trn mrng
V d
1 1 1 1 2
2 1 3 0 1
3 4 2 2 5
2 3 1 1 3
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
Tm nghim tng qut ca hphng trnh bit ma trn mrng
1 1 2 0 1
V d
2 3 1 2 43 4 5 1 3
1 2 3 1 0
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I. Hphng trnh tuyn tnh tng qut------------------------------------------------------------------------------------------------------------
-
Tm tt ccc gi trca tham sm phng trnh sau c nghim
V d
1 1 1m
2
1 1 ,
1 1
m m
m m
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
1 1 1 1
Tm tt ccc gi trca tham sm phng trnh sau c nghimExample
2 3 1 4
3 4 1m m
+
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I. I. Hphng trnh tuyn tnh tng qut
V dTm tt ccc gi trca tham sm phng trnh sau c nghim
duy nht1 1 1 1 1
2 1 3 1 2,
3 4 2 0 6
2 1 0 1m m
I. Hphng trnh tuyn tnh tng qut---------------------------------------------------------------------------------------------------------------------------
V dTm tt ccc gi trca tham sm phng trnh sau c nghim
duy nht
2 3 1 4 0
23 2 1 5 71 1 1m m
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II. Hthun nht.---------------------------------------------------------------------------------------------------------------------------
H phng trnh tuyn tnh c gi l thun nht nu tt ccc h s t do b1, b2, , bmu bng 0.
nh ngha h thun nht.
x1 = x2 = = xn = 0.
Nghim nyc gi l nghim tm thng.
H thun nht ch c nghim duy nht bng khng khi v chkhi r (A) = n = s n .
II. Hthun nht.---------------------------------------------------------------------------------------------------------------------------
H thun nht AX = 0 c nghim khng tm thng khi v chkhi r(A) < n.
H thun nht A X = 0 , vi A l m a t rn vung c nghim khngtm thng (nghim khc 0) khi v ch khi det(A) = 0.
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II. Hthun nht.---------------------------------------------------------------------------------------------------------------------------
Tm nghim tng qut ca h phng trnh.
V d
1 2 3 42 2 0x x x+ + + =
1 2 3 4
1 2 3 43 6 4 0
x x x x
x x x x
+ + + =
+ + + =
II. Hthun nht.---------------------------------------------------------------------------------------------------------------------------
Gia nhng nghim ca h
V d
2 0
2 4 0
y z
x y z
+ + =
+ + =
2 0x y z+ =
tm nghim tha biu thc y x y = 2 z
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II. Hthun nht.---------------------------------------------------------------------------------------------------------------------------
Gi s Almat rn ca h thun nht c 4 p hng trnh v 8n,
gi s c 5n t do. Tm r(A)?
V d
Gii thch v sao h phng trnh thun nht c m p hng trnh,nn vim
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Trng H Bch khoa tp HCh Minh
Khoa Khoa hc ng dng - Bmn Ton ng dng------------------------------------------------------
ai so tuyen tnh
Chng 4: KHONG GIAN VECT
Giang vien TS. ang Van Vinh
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Ni dung---------------------------------------------------------------------------------------------------------------------------
I nh ngha va V du
II oc lap tuyen tnh, phu thuoc tuyen tnh
III Han cua ho vect
V Khong gian con.
IV C s va so chieu
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I. nh ngha va cac v du---------------------------------------------------------------------------------------------------------------------------
==
Tp khc rngV Hai php ton
Nhn vctvi 1 sCng
8 tin
KHNG GIAN VCTV3. Tn ti vc tkhng, k hiu 0 sao chox + 0 = x
4. Mixthuc V, tn ti vect, k hiu xsao cho x + (-x) = 0
8.1x = x
5. Vi mi s v mi vectorx:, K ( ) x x x + = +
6. Vi mi s , vi mi :K x , y V ( x y ) x y + = +
7.( ) x ( x ) =
I. nh ngha v cc v d---------------------------------------------------------------------------------------------------------------------------
Tnh cht ca khng gian vct
1) Vctkhng l duy nht.
2) Phn t i xng ca vctxl duy nht.
3) 0x = 0
5) -x = (-1)x
Vi mi vectxthucVv mi s :K
4) 0 0 =
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I. nh ngha v cc v d----------------------------------------------------------------------------------------------------------
--
}{ RxxxxV i = ),,( 3211
),,(),,(),,( 332211321321 yxyxyxyyyxxxyx +++=+=+
V d1
nh ngha php cng hai vctnhsau:
nh ngha php nhn vctvi mt sthc nhsau:
),,(),,( 321321 xxxxxx ==
=
=
=
=
33
22
11
yx
yx
yx
yx
V1 - Khng gian vct trn trngsthc3R
nh ngha sbng nhau:
I. nh ngha v cc v d---------------------------------------------------------------------------------------------------------------------------
RcbacbxaxV ++= ,,2
2
V d2
nh ngha php cng hai vct: l php cng hai a thcthng thng, bitphthng.
nh ngha php nhn vctvi mt s: l php nhna thc
V2 - Khng gian vct ][2 xP
vi mts thcthng thng, bi tph thng.
nh ngha sbng nhau: hai vc tbng nhau nu hai athc bng nhau, tc l cc hstngng bng nhau).
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I. nh ngha v cc v d---------------------------------------------------------------------------------------------------------------------------
= Rdcba
dc
baV ,,,3
V d3
nh ngha php cng hai vct: l php cng hai ma trnbit trong chng ma trn.
V3 - Khng gian vct ][2 RM
vi mt s bit.
nh ngha sbng nhau ca hai vct: hai vc tbng nhauhai ma trn bng nhau.
I. nh ngha v cc v d----------------------------------------------------------------------------------------------------------
--
}{4 1 2 3 1 2 32 3 0ix x x x R x x x= + + =( , , )
Php cng hai vctv nhn vctvi mt sging nhtrong v d1.
V d4
V4 - l KGVT
CH : C nhiu cch khc nhau nh ngha hai phpton trn V1, ( hocV2, hocV3) sao cho V1 ( hocV2, hocV3) l khng gian vct.
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I. nh ngha v cc v d----------------------------------------------------------------------------------------------------------
--
}{5 1 2 3 1 2 32 1i( x ,x ,x ) x R x x x= + =
Php cng hai vctv nhn vctvi mt sging nh
V d5
.
V4 -KHNGl KGVT
4 4(1,2,1) , (2,3,2)= = x V y V
4)3,5,3( Vyx =+
II. c lp tuyn tnh---------------------------------------------------------------------------------------------------------------------------
V- KGVT trn K
1 2{ , ,..., }mM x x x=
Tp con
MPTTT1 2, , , m K khngng thi bng 0
1 1 2 2 0m mx x + + + =
M c lp tuyn tnh1 1 2 2 0m mx x + + + =
1 2 0m = = =
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II. c lp tuyn tnh---------------------------------------------------------------------------------------------------------------------------
V- KGVT trn K
1 2{ , ,..., }mM x x x=
Tp con
1 2, , , m K
1 1 2 2 m mx x x x = + + +
Vector x thuc Vc gi lThp tuyn tnhcaM,nu
II. c lp tuyn tnh---------------------------------------------------------------------------------------------------------------------------
{ (1,1,1) ; ( 2 ,1, 3 ) , (1, 2 , 0 ) }M =
Trong khng gian R3cho hvc tV d5
1. Hi Mc lp tuyn tnh hay phthuc tuyn tnh?
2. Vctx = (2,-1,3) c l thp tuyn tnh ca hM?
c u . s , , , , , , =
2 2 3 0 0 0( , , ) ( , , ) + + + + + =
2 0
2 0
3 0
+ + =
+ + = + =
1 2 1
1 1 2
1 3 0
A
=
2r( A ) =
Hc v snghim, suy ra M phthuc tuyn tnh
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