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Slide P- 1
Chapter P
Prerequisites
P.1
Real Numbers
Slide P- 4
Quick Review
1. List the positive integers between -4 and 4.
2. List all negative integers greater than -4.
3. Use a calculator to evaluate the expression
2 4.5 3. Round the value to two deci
2.3 4.
1
5
,2,3
-3,-2,-1
3
mal places.
4. Evaluate the algebraic expression for the given values
of the variable. 2 1, 1,1.5
5. List the possible remainders when the positive integer
i
2.73
-4,
s divid
5.375
1,2,ed by 6.
x x x
n
3,4,5
Slide P- 5
What you’ll learn about
Representing Real Numbers Order and Interval Notation Basic Properties of Algebra Integer Exponents Scientific Notation
… and whyThese topics are fundamental in the study of mathematics and science.
Slide P- 6
Real Numbers
A real number is any number that can be written as a decimal.
Subsets of the real numbers include: The natural (or counting) numbers: {1,2,3…} The whole numbers: {0,1,2,…} The integers: {…,-3,-2,-1,0,1,2,3,…}
Slide P- 7
Rational Numbers
Rational numbers can be represented as a ratio a/b where a and b are integers and b ≠ 0.
The decimal form of a rational number either terminates or is indefinitely repeating.
Slide P- 8
The Real Number Line
Slide P- 9
Order of Real Numbers
Let a and b be any two real numbers.
Symbol Definition Reada>b a – b is positive a is greater than b
a<b a – b is negative a is less than b
a≥b a – b is positive or zero a is greater than or equal to b
a≤b a – b is negative or zero a is less than or equal to b
The symbols >, <, ≥, and ≤ are inequality symbols.
Slide P- 10
Trichotomy Property
Let a and b be any two real numbers.
Exactly one of the following is true:
a < b, a = b, or a > b.
Slide P- 11
Example Interpreting Inequalities
Describe the graph of x > 2.
Slide P- 12
Example Interpreting Inequalities
Describe the graph of x > 2.
The inequality describes all real numbers greater than 2.
Slide P- 13
Bounded Intervals of Real Numbers
Let a and b be real numbers with a < b.
Interval Notation Inequality Notation
[a,b] a ≤ x ≤ b
(a,b) a < x < b
[a,b) a ≤ x < b
(a,b] a < x ≤ b
The numbers a and b are the endpoints of each interval.
Slide P- 14
Unbounded Intervals of Real Numbers
Let a and b be real numbers.Interval Notation Inequality Notation[a,∞) x ≥ a(a, ∞) x > a (-∞,b] x ≤ b(-∞,b) x < b
Each of these intervals has exactly one endpoint, namely a or b.
Slide P- 15
Graphing Inequalities
x > 2
x < -3 (-,-3]
(2,)
-1< x < 5 (-1,5]
Slide P- 16
Properties of Algebra
Let , , and be real numbers, variables, or algebraic expressions.
Addition:
Multiplication
Addition: ( ) ( )
Multiplication: ( )
u v w
u v v u
uv vu
u v w u v w
uv w u
1. Communative Property
2. Associative Property
( )
Addition: 0
Multiplication: 1
vw
u u
u u
3. Identity Property
Slide P- 17
Properties of Algebra
Let , , and be real numbers, variables, or algebraic expressions.
Addition: (- ) 0
1Mulitiplication: 1, 0
Multiplication over addition:
( )
u v w
u u
u uu
u v w uv uw
4. Inverse Property
5. Distributive Property
( )
Multiplication over subtraction:
( )
( )
u v w uw vw
u v w uv uw
u v w uw vw
Slide P- 18
Properties of the Additive Inverse
Let , , and be real numbers, variables, or algebraic expressions.
1. ( ) ( 3) 3
2. ( ) ( ) ( 4)3 4( 3) 12
u v w
u u
u v u v uv
Property Example
3. ( )( ) ( 6)( 7) 42
4. ( 1) ( 1)5 5
5. ( ) ( ) ( ) (7 9) ( 7) ( 9) 16
u v uv
u u
u v u v
Slide P- 19
Exponential Notation
n factors... ,
Let be a real number, variable, or algebraic expression and
a positive integer. Then where is the
, is the , and is the ,
read as " to
n
n
a a a a
a n
a n
a a
a
exponent base th power of n a
the th power."n
Slide P- 20
Properties of Exponents
Let and be a real numbers, variables, or algebraic expressions
and and be integers. All bases are assumed to be nonzero.
1. m n m n
u v
m n
u u u Property Example
3 4 3 4 7
9
9 4 5
4
0 0
- -3
3
5 5 5 5
2.
3. 1 8 1
1 14.
5. (
m
m n
n
n
n
u xu x x
u xu
u yu y
5 5 5 5
2 3 2 3 6
77
7
) (2 ) 2 32
6. ( ) ( )
7.
m m m
m n mn
mm
m
uv u v z z z
u u x x x
u u a a
v v b b
Slide P- 21
Example Simplifying Expressions Involving Powers
2 3
1 2Simplify .
u v
u v
2 3 2 1 3
1 2 2 3 5
u v u u u
u v v v v
Slide P- 22
Example Converting to Scientific Notation
Convert 0.0000345 to scientific notation.
-50.0000345 3.45 10
Slide P- 23
Example Converting from Scientific Notation
Convert 1.23 × 105 from scientific notation.
123,000
P.2
Cartesian Coordinate System
Slide P- 25
Quick Review Solutions
2 2
2 2
2 2
-5 31. Find the distance between and .
4 2Use a calculator to evaluate the expression. Round answers
to two decimal places.
2. 8 6
-12 83.
2
4. 3 5
5. 2
2.75
10
-2
5.83
3.5 1 3 61
Slide P- 26
What you’ll learn about
Cartesian Plane Absolute Value of a Real Number Distance Formulas Midpoint Formulas Equations of Circles Applications
… and whyThese topics provide the foundation for the material that will be covered in this textbook.
Slide P- 27
The Cartesian Coordinate Plane
Slide P- 28
Quadrants
Slide P- 29
Absolute Value of a Real Number
The is
, if 0
| | if 0.
0, if 0
a a
a a a
a
absolute value of a real number a
Slide P- 30
Properties of Absolute Value
Let and be real numbers.
1. | | 0
2. | - | | |
3. | | | || |
| |4. , 0
| |
a b
a
a a
ab a b
a ab
b b
Slide P- 31
Distance Formula (Number Line)
Let and be real numbers. The is | | .
Note that | | | | .
a b a b
a b b a
distance between and a b
Slide P- 32
Distance Formula (Coordinate Plane)
2 2
1 2 1 2
The in the
coordinate plane is .d x x y y
distance between points and 1 1 2 2
d P(x , y ) Q(x , y )
Slide P- 33
The Distance Formula using the Pythagorean Theorem
Slide P- 34
Midpoint Formula (Number Line)
The is
.2
a bmidpoint of the line segment with endpoints and a b
Slide P- 35
Midpoint Formula (Coordinate Plane)
The is
, .2 2
a c b d
midpoint of the line segment with endpoints ( ) and ( )a,b c,d
Slide P- 36
Find the distance and midpoint for the line segment joinedby A(-2,3) and B(4,1).
A(-2,3)
B(4,1)
22 )13()42(),( BAd
22 )2()6(),( BAd
40),( BAd 104102
2
)13(,
2
)42(
2
4,
2
2= (1,2)
Distance and Midpoint Example
Slide P- 37
Show that A(4,1), B(0,3), and C(6,5) are vertices of an isosceles triangle.
A(4,1)
B(0,3)
C(6,5)
52)31()04(),( 22 BAd
102)53()60(),( 22 CBd
52)15()64(),( 22 CAd
Since d(AC) = d(AB) , ΔABC is isosceles
Example Problem
Slide P- 38
P is a point on the y-axis that is 5units from the point Q (3,7). Find P.
5)7()03(),( 22 yQPdP
Q(3,7)
(0,y)
549149 2 yy
558142 yy
2558142 yy
033142 yy 0)3)(11( yy y = 3, y = 11
The point P is (0,3) or (0,11)
Example
Slide P- 39
Prove that the diagonals of a rectangle are congruent.
Coordinate Proofs
Given ABCD is a rectangle.Prove AC = BD
A(0,0)
B(0,a)
D(b,0)
C(b,a)
2222 )0()0( ababdAC
2222 )0()0( ababdBD
Since AC= BD, the diagonals of a square are congruent
Slide P- 40
Slide P- 41
Standard Form Equation of a Circle
2 2 2
The with center ( , )
and radius is ( ) ( ) .
h k
r x h y k r standard form equation of a circle
Slide P- 42
Standard Form Equation of a Circle
Slide P- 43
Example Finding Standard Form Equations of Circles
Find the standard form equation of the circle with center
(2, 3) and radius 4.
2 2 2
2 2
( ) ( ) where 2, 3,and 4.
Thus the equation is ( 2) ( 3) 16.
x h y k r h k r
x y
P.3
Linear Equations and Inequalities
Slide P- 45
Quick Review
Simplify the expression by combining like terms.
1. 2 4 2 3
2. 3(2 2) 4( 1)
Use the LCD to combine the fractions. Simplify the
resulting fraction.
3 43.
3 3
6 4 10
7
24.
4 3
x y
x y
x x y y x
x y
x xx x
x
25.
7 6
122
2 2
y
x
y
y
Slide P- 46
What you’ll learn about
Equations Solving Equations Linear Equations in One Variable Linear Inequalities in One Variable
… and whyThese topics provide the foundation for algebraic techniques needed throughout this textbook.
Slide P- 47
Properties of Equality
Let , , , and be real numbers, variables, or algebraic expressions.
If , then .
If
u v w z
u u
u v v u
1. Reflexive
2. Symmetric
3. Transitive , and , then .
If and , then .
If and , then .
u v v w u w
u v w z u w v z
u v w z uw vz
4. Addition
5. Multiplication
Slide P- 48
Linear Equations in x
A linear equation in x is one that can be written in the form ax + b = 0, where a and b are real numbers with a ≠ 0.
Slide P- 49
Operations for Equivalent EquationsAn equivalent equation is obtained if one or more of the following
operations are performed.
1. Combine like terms,
Operation Given Equation Equivalent Equation
3 1 2 3
9 3
reduce fractions, and
remove grouping symbols
2. Perform the same
operation on both sides.
(a) Add ( 3) 3 7 4
(
x x x
x x
b) Subtract (2 ) 5 2 4 3 4
(c) Multiply by a
nonzero constant (1/3) 3 12 4
(d) Divide by a constant
x x x x
x x
nonzero term (3) 3 12 4x x
Slide P- 50
Example Solving a Linear Equation Involving Fractions
10 4Solve for . 2
4 4
y yy
10 42
4 410 4
4 2 4 Multiply by the LCD4 4
10y 4 8 Distributive Property
9 12 Simplify
4
3
y y
y y
y
y
y
Slide P- 51
Linear Inequality in x
A is one that can be written in the form
0, 0, 0, or 0, where and are
real numbers with 0.
ax b ax b ax b ax b a b
a
linear inequality in x
Slide P- 52
Properties of Inequalities
Let , , , and be real numbers, variables, or algebraic expressions,
and a real number.
If , and , then .
If
u v w z
c
u v v w u w
u v
1. Transitive
2. Addition then .
If and then .
If and 0, then .
If and 0, then .
T
u w v w
u v w z u w v z
u v c uc vc
u v c uc vc
3. Multiplication
he above properties are true if < is replaced by . There are
similar properties for > and .
P.4
Lines in the Plane
Slide P- 54
Quick Review
Solve for .
1. 50 100 200
2. 3(1 2 ) 4( 2) 10
Solve for .
3. 2 3 5
4. 2 3( )
7 25. Simplify t
2
1
2
2
he fraction. 1
5
3
3
70 (
45
)
x
x
x x
y
x
x
x
xy
xy
y
x x y y
Slide P- 55
What you’ll learn about
Slope of a Line Point-Slope Form Equation of a Line Slope-Intercept Form Equation of a Line Graphing Linear Equations in Two Variables Parallel and Perpendicular Lines Applying Linear Equations in Two Variables
… and whyLinear equations are used extensively in applications involving business and behavioral science.
Slide P- 56
Slope of a Line
Slide P- 57
Slope of a Line
1 1
2 1
2 2
2 1
1 2
The slope of the nonvertical line through the points ( , )
and ( , ) is .
If the line is vertical, then and the slope is undefined.
x y
y yyx y m
x x x
x x
Slide P- 58
Example Finding the Slope of a Line
Find the slope of the line containing the points (3,-2) and (0,1).
2 1
2 1
1 ( 2) 31
0 3 3
Thus, the slope of the line is 1.
y ym
x x
Slide P- 59
Point-Slope Form of an Equation of a Line
1 1 1 1
The of an equation of a line that passes through
the point ( , ) and has slope is ( ).x y m y y m x x point - slope form
Slide P- 60
Point-Slope Form of an Equation of a Line
Slide P- 61
Slope-Intercept Form of an Equation of a Line
The slope-intercept form of an equation of a line with slope m
and y-intercept (0,b) is y = mx + b.
Slide P- 62
Forms of Equations of Lines
General form: Ax + By + C = 0, A and B not both zero
Slope-intercept form: y = mx + b
Point-slope form: y – y1 = m(x – x1)
Vertical line: x = a
Horizontal line: y = b
Slide P- 63
Graphing with a Graphing Utility
To draw a graph of an equation using a grapher:
1. Rewrite the equation in the form y = (an expression in x).
2. Enter the equation into the grapher.
3. Select an appropriate viewing window.
4. Press the “graph” key.
Slide P- 64
Viewing Window
Slide P- 65
Parallel and Perpendicular Lines
1 2
1. Two nonvertical lines are parallel if and only if their
slopes are equal.
2. Two nonvertical lines are perpendicular if and only
if their slopes and are opposite reciprocals.
That is, if and only
m m
1
2
1 if .m
m
Slide P- 66
Example Finding an Equation of a Parallel Line
Find an equation of a line through (2, 3) that is parallel to
4 5 10.x y
Find the slope of 4 5 10.
5 4 10
4 42 The slope of this line is .
5 5Use point-slope form:
43 2
5
x y
y x
y x
y x
or y = mx + b
5
1
5
4
5
15
83
)2(5
43
5
4
xyb
b
b
bxy
Slide P- 67
Determine the equation of the line (written in standard form) that passes through the point (-2, 3) and is perpendicular to the line 2y – 3x = 5.
Example
P.5
Solving Equations Graphically, Numerically, and Algebraically
Slide P- 69
Quick Review Solutions
2 2
3 2
4 2 2
2
2
4 4
8 2 3
1
Expand the product.
1. 2
2. 2 1 4 3
Factor completely.
3. 2 2
4. 5 36
5. Combine the fractions and reduce the resulting fraction
to low
2
9 2
e
1
2
x xy y
x x
x x x
y y
x y
x x
x x
y y
x
y
22
st terms. 2 1 11
5 2
2 1
xx
x x
x
x x
Slide P- 70
What you’ll learn about
Solving Equations Graphically Solving Quadratic Equations Approximating Solutions of Equations Graphically Approximating Solutions of Equations Numerically with
Tables Solving Equations by Finding Intersections
… and whyThese basic techniques are involved in using a graphing utility to solve equations in this textbook.
Slide P- 71
Example Solving by Finding x-Intercepts
2Solve the equation 2 3 2 0 graphically.x x
Slide P- 72
Example Solving by Finding x-Intercepts
2Solve the equation 2 3 2 0 graphically.x x
2Find the -intercepts of 2 3 2.
Use the Trace to see that ( 0.5,0) and (2,0) are -intercepts.
Thus the solutions are 0.5 and 2.
x y x x
x
x x
Slide P- 73
Zero Factor Property
Let a and b be real numbers.
If ab = 0, then a = 0 or b = 0.
Slide P- 74
Quadratic Equation in x
A quadratic equation in x is one that can be written in the form ax2 + bx + c = 0, where a, b, and c are real numbers with a ≠ 0.
Slide P- 75
Completing the Square
2 2
2 2
2
22
To solve by completing the square, add ( / 2) to
both sides of the equation and factor the left side of the new
equation.
2 2
2 4
x bx c b
b bx bx c
b bx c
Slide P- 76
Quadratic Equation
2
2
The solutions of the quadratic equation 0, where
0, are given by the
4.
2
ax bx c
a
b b acx
a
quadratic formula
Slide P- 77
Example Solving Using the Quadratic Formula
2Solve the equation 2 3 5 0.x x
2
2
2, 3, 5
4
2
3 3 4 2 5
2 2
3 49
43 7
4
5 or 1.
2
a b c
b b acx
a
x x
0)1)(52( xx
01or052 xx
1or 2
5 xx
Slide P- 78
Solving Quadratic Equations Algebraically
These are four basic ways to solve quadratic equations
algebraically.
1. Factoring
2. Extracting Square Roots
3. Completing the Square
4. Using the Quadratic Formula
Slide P- 79
Agreement about Approximate Solutions
For applications, round to a value that is reasonable for the context of the problem. For all others round to two decimal places unless directed otherwise.
Slide P- 80
Example Solving by Finding Intersections
Solve the equation | 2 1| 6.x
Slide P- 81
Example Solving by Finding Intersections
Solve the equation | 2 1| 6.x
Graph | 2 1| and 6. Use Trace or the intersect feature
of your grapher to find the points of intersection.
The graph indicates that the solutions are 2.5 and 3.5.
y x y
x x
P.6
Complex Numbers
Slide P- 83
Quick Review
2
2
2
Add or subtract, and simplify.
1. (2 3) ( 3)
2. (4 3) ( 4)
Multiply and simplify.
3. ( 3)( 2)
4. 3 3
5. (2 1)(
6
3 7
6
3
6 135 53 )
x x
x x
x x
x
x
x x
x
x x
x x
x x
Slide P- 84
What you’ll learn about
Complex Numbers Operations with Complex Numbers Complex Conjugates and Division Complex Solutions of Quadratic Equations
… and why
The zeros of polynomials are complex numbers.
Slide P- 85
Find two numbers whose sum is 10 and whose product is 40.
x = 1st number 10 – x = 2nd number
x(10 – x) = 40
Complex Numbers
Slide P- 86
x(10 – x) = 40 10x – x2 = 40 x2 – 10x = -40 x2 – 10x + 25 = -40 +25 (x – 5)2 = -15
155 x
155155 , x
Complex Numbers
Slide P- 87
)) 15(5 15(5
)) 15(5 15(5
)15(155 15525 40
10
Complex Numbers
Slide P- 88
The imaginary number i is the
square root of –1.
1i 12 i
i416116
1010 i
Complex Numbers
Slide P- 89
Imaginary numbers are not real numbers, so all the rules do not apply.
Example: The product rule does not apply:
100205
100205205 2iii
10101
Complex Numbers
Slide P- 90
If a and b are real numbers, then
a + bi is a complex number. a is the real part. bi is the imaginary part.
The set of complex numbers consist of all the real numbers and all the imaginary numbers
Complex Numbers
Slide P- 91
A complex number is any number that can be written in the form a + bi, where a and b are real numbers. The real number a is the real part, the real number b is the imaginary part, and a + bi is the standard form.
Complex Numbers
Slide P- 92
Examples of complex numbers: 3 + 2i 8 - 2i 4 (since it can be written as 4 + 0i).
The real numbers are a subset of the complex numbers.
-3i (since it can be written as 0 – 3i).
Complex Numbers
Slide P- 93
i 12i 11
2
3i iiii 12
4i 11 222 i
Complex Numbers
Slide P- 94
5i iiii 14
6i 11124 ii7i iiii 134
8i 11144 ii
Complex Numbers
Slide P- 95
* i -1 -i 1
-1 -i 1 i
-i 1 i -1
1 i -1 -i
i -1 -i 1
i
-1
-i
1
Complex Numbers
Slide P- 96
35i iiii 8384 1
Evaluate:
24i 11 664 i
Complex Numbers
Slide P- 97
Addition and Subtraction of Complex Numbers
If a + bi and c + di are two complex numbers, then
Sum: (a + bi ) + (c + di ) = (a + c) + (b + d)i,
Difference: (a + bi ) – (c + di ) = (a - c) + (b -d)i.
Slide P- 98
Example Multiplying Complex Numbers
Find 3 2 4 .i i
Slide P- 99
Example Multiplying Complex Numbers
Find 3 2 4 .i i
2
3 2 4
12 3 8 2
12 5 2( 1)
12 5 2
14 5
i i
i i i
i
i
i
Slide P- 100
Complex Conjugate
The of the complex number is
.
z a bi
z a bi a bi
complex conjugate
Slide P- 101
Discriminant of a Quadratic Equation
2
2
2
2
For a quadratic equation 0, where , , and are
real numbers and 0.
if 4 0, there are two distinct real solutions.
if 4 0, there is one repeated real solution.
if 4 0, the
ax bx c a b c
a
b ac
b ac
b ac
re is a complex pair of solutions.
Slide P- 102
Example Solving a Quadratic Equation
2Solve 2 0.x x
Slide P- 103
Example Solving a Quadratic Equation
2Solve 2 0.x x
2
1, and 2.
1 1 4 1 2
2 1
1 7
2
1 7
2
1 7 1 7So the solutions are and .
2 2
a b c
x
i
i ix x
Slide P- 104
When dividing a complex number by a real number, divide each part of the complex number by the real number.
4
86 i4
8
4
6 i i2
2
3
Complex Numbers
Slide P- 105
The numbers (a + bi ) and (a – bi ) are complex conjugates.
The product (a + bi )·(a – bi ) is the real number a 2 + b 2.
Show: (3 + 2i) (3 – 2i) = 3 2 + 2 2.
Complex Numbers
Slide P- 106
Show: (3 + 2i) (3 – 2i) = 3 2 + 2 2.
(3 + 2i) (3 – 2i) = 3.3 + 3(-2i) + 2i .3 + 2i (-2i)
= 3 2 – 6i + 6i – 2 2i 2
= 3 2 – 2 2(-1)
= 3 2 + 2 2
= 9 + 4
= 13
Complex Numbers
Slide P- 107
When dividing a complex number by a complex number, multiply the denominator and numerator by the conjugate of the denominator.
i
i
1
32
i
i
i
i
1
1
1
32
2
2
1
3322
i
iii
11
132
i
Complex Numbers
Slide P- 108
11
132
i
2
5 i
i2
1
2
5
Complex Numbers
Slide P- 109
Complex Numbers
P.7
Solving Inequalities Algebraically and Graphically
Slide P- 111
Quick Review
2
2
2
Solve for .
1. 3 2 1 9
2. | 2 1| 3
3. Factor completely. 4 9
494. Reduce the fraction to lowest terms.
7
5. Add the fractions and
2 4
2 or 1
2 3
simpli
2 3
7
fy.
x
x
x
x
x
x
x x
x x
x
xx
xx
2
2
2
3 22
1
xx
xx x
x
x
Slide P- 112
What you’ll learn about
Solving Absolute Value Inequalities Solving Quadratic Inequalities Approximating Solutions to Inequalities Projectile Motion
… and whyThese techniques are involved in using a graphing utility to solve inequalities in this textbook.
Slide P- 113
Solving Absolute Value Inequalities
Let be an algebraic expression in and let be a real number
with 0.
1. If | | , then is in the interval ( , ). That is,
| | if and only if .
2. If | | , then is in the interval (
u x a
a
u a u a a
u a a u a
u a u
, ) or ( , ). That is,
| | if and only if or .
The inequalities < and > can be replaced with and ,
respectively.
a a
u a u a u a
Slide P- 114
Solve 2x – 3 < 4x + 5 -2x < 8 x > -4
-5 -4 -3
Solve |x – 2| < 1 -1 < x – 2 < 1 1 < x < 3
0 1 2 3 4
Solving Absolute Value Inequalities
Slide P- 115
Solve -1 < 3 – 2x < 5 -4 < -2x < 2 2 > x > -1 -1 < x < 2
Solve |x – 1| > 3 -3 > x – 1 or x – 1 > 3 -2 > x or x > 4 x < -2 or x > 4
-2 -1 0 1 2 3 -2 -1 0 1 2 3 4
Solving Absolute Value Inequalities
Slide P- 116
•|2x – 6| < 4•-4 < 2x – 6 < 4•2 < 2x < 10•1< x < 5
-1 0 1 2 3 4 5( )
•|3x – 1| > 2•3x – 1 < -2 or 3x – 1 > 2•3x < -1 or 3x > 3•x < -1/3 or x > 1
-1 0 1 2 3 4 5
] [
Solving Absolute Value Inequalities
Slide P- 117
Example Solving an Absolute Value Inequality
Solve | 3 | 5.x
| 3 | 5
5 3 5
8 2
As an interval the solution in ( 8,2).
x
x
x
Slide P- 118
Example Solving a Quadratic Inequality
2
2
Solve 3 2 0
( 2)( 1) 0
2 or 1.
Use these solutions and a sketch of the equation
3 2 to find the solution to the inequality
in interval form ( 2, 1).
x x
x x
x x
y x x
-2 -1
+++0--------0+++
Slide P- 119
Solve x2 – x – 20 < 0
1. Find critical numbers (x + 4)(x - 5) < 0x = -4, x = 5
2. Test Intervals (-∞,-4) (-4,5) and (5, ∞)3. Choose a sample in each interval x = -5 (-5)2 – (-5) – 20 = Positive x = 0 (0)2 - (0) - 20 = Negative x = 6 (6)2 – 3(6) = Positive
Solution is (-4,5)
-4 5
+++0-------0+++
Example Solving a Quadratic Inequality
Slide P- 120
Solve x2 – 3x > 0
1. Find critical numbers x(x - 3) > 0x = 0, x = 3
2. Test Intervals (-∞,0) (0,3) and (3, ∞)3. Choose a sample in each interval x = -1 (-1)2 – 3(-1) = Positive x = 1 (1)2 - 3(1) = Negative x = 4 (4)2 – 3(4) = Positive
Solution is (-∞,0) or (3, ∞)
0 3
+++0------0+++
Example Solving a Quadratic Inequality
Slide P- 121
Solve x3 – 6x2 + 8x < 0
1. Find critical numbers x(x2 – 6x + 8) < 0x(x – 2)(x – 4) x = 0, x = 2, x = 4
2. Test Intervals (-∞,0) (0,2) (2,4) and (4, ∞)3. Choose a sample in each interval x = -5 (-5)3 – 6(-5)2 + 8(-5) = Negative x = 1 (-1)3 – 6(-1)2 + 8(-1) = Positive x = 3 (3)3 – 6(3)2 + 8(3) = Negative x = 5 (5)3 – 6(5)2 + 8(5) = Positive
Solution is (-∞,0] U [2,4]
0 2 4
-----0++0----0+++
Example Solving a Quadratic Inequality
Slide P- 122
Projectile Motion
Suppose an object is launched vertically from a point so feet above the ground with an initial velocity of vo feet per second. The vertical position s (in feet) of the object t seconds after it is launched is
s = -16t2 + vot + so.
Slide P- 123
Chapter Test
-6
2
1. Write the number in scientific notation.
The diameter of a red blood corpuscle is about 0.000007 meter.
2. Find the standard form equation for the circle with center (5, 3)
and radius 4.
7 10
5x
2
3. Find the slope of the line through the points ( 1, 2) and (4, 5).
4. Find the equation of the line through (2, 3) and perpendicular
to the line 2 5 3.
5. Solve the equation al
3 16
3
5
58
ge
2
b
y
yx xy
2
2 5 1raically.
3 2 3
6. Solve the equation algebraically. 6 7 3
9
51 3
or 3 2
xx x
x x x x
Slide P- 124
Chapter Test
2
1 or 1
22
( , 2] ,
7. Solve the equation algebraically. | 4 1 | 3
8. Solve the inequality. | 3 4 | 2
9. Solve the inequality. 4 12 9 0
10. Perform the indicated operation, and wri
3
,
x
x
x
x
x
x
te the result
in standard form. (5 7 ) (3 2 ) 2 5i i i