1
Slide P- 1Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Chapter P
Prerequisites
2
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.1
Real Numbers
Slide P- 4Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 decimal places.
2.3 4.5
4. Eva
−
−
3
luate the algebraic expression for the given values
of the variable. 2 1, 1,1.5
5. List the possible remainders when the positive integer
is divided by 6.
x x x
n
+ − = −
3
Slide P- 5Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
{ }
{ }
( )
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- 6Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
What you’ll learn about
� Representing Real Numbers
� Order and Interval Notation
� Basic Properties of Algebra
� Integer Exponents
� Scientific Notation
… and why
These topics are fundamental in the study of
mathematics and science.
4
Slide P- 7Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 8Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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.
5
Slide P- 9Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
The Real Number Line
Slide P- 10Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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.
6
Slide P- 11Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 12Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Interpreting Inequalities
Describe the graph of x > 2.
7
Slide P- 13Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Interpreting Inequalities
Describe the graph of x > 2.
The inequality describes all real numbers greater than 2.
Slide P- 14Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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.
8
Slide P- 15Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 16Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
9
Slide P- 17Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 18Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
− − = − − =
− = − − = −
− + = − + − − + = − + − = −
10
Slide P- 19Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 20Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 Example3 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 x
u
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
⋅
= = =
= = =
= =
11
Slide P- 21Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Simplifying Expressions
Involving Powers2 3
1 2Simplify .
u v
u v
−
−
Slide P- 22Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Simplifying Expressions
Involving Powers2 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
−
−= =
12
Slide P- 23Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Converting to Scientific
Notation
Convert 0.0000345 to scientific notation.
Slide P- 24Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Converting to Scientific
Notation
Convert 0.0000345 to scientific notation.
-5
0.0000345 3.45 10= ×
13
Slide P- 25Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Converting from Scientific
Notation
Convert 1.23 × 105 from scientific notation.
Slide P- 26Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Converting from Scientific
Notation
Convert 1.23 × 105 from scientific notation.
123,000
14
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.2
Cartesian Coordinate System
Slide P- 28Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review
( ) ( )
2 2
2 2
2 2
-5 31. Find the distance between and .
4 2
Use a calculator to evaluate the expression. Round answers
to two decimal places.
2. 8 6
-12 83.
2
4. 3 5
5. 2 5 1 3
+
+
+
− + −
15
Slide P- 29Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
( ) ( )
2 2
2 2
2 2
-5 31. Find the distance between and .
4 2
Use 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- 30Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
What you’ll learn about
� Cartesian Plane
� Absolute Value of a Real Number
� Distance Formulas
� Midpoint Formulas
� Equations of Circles
� Applications
… and why
These topics provide the foundation for the material that will be
covered in this textbook.
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Slide P- 31Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
The Cartesian Coordinate Plane
Slide P- 32Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quadrants
17
Slide P- 33Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 34Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
≥
=
=
= ≠
18
Slide P- 35Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 36Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 )
19
Slide P- 37Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
The Distance Formula using the
Pythagorean Theorem
Slide P- 38Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Midpoint Formula (Number Line)
The is
.2
a b+
midpoint of the line segment with endpoints and a b
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Slide P- 39Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 40Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
21
Slide P- 41Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Standard Form Equation of a Circle
Slide P- 42Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Finding Standard Form
Equations of Circles
Find the standard form equation of the circle with center
(2, 3) and radius 4.−
22
Slide P- 43Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
− + − = = = − =
− + + =
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.3
Linear Equations and Inequalities
23
Slide P- 45Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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.
24.
4 3
25. 2
x x y y x
x y
x x
x x
y
+ − − −
− + −
+
++
+
Slide P- 46Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
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 x
x x
x
+ − − −
− + −
+
+
−
+
+ −
25.
7 6
12
22
2
y
x
y
y+
+
+
24
Slide P- 47Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
What you’ll learn about
� Equations
� Solving Equations
� Linear Equations in One Variable
� Linear Inequalities in One Variable
… and why
These topics provide the foundation for algebraic
techniques needed throughout this textbook.
Slide P- 48Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
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Slide P- 49Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 50Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Operations for Equivalent Equations
An 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= =
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Slide P- 51Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving a Linear Equation
Involving Fractions
10 4Solve for . 2
4 4
y yy
−= +
Slide P- 52Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving a Linear Equation
Involving Fractions
10 4Solve for . 2
4 4
y yy
−= +
10 42
4 4
10 44 2 4 Multiply by the LCD
4 4
10y 4 8 Distributive Property
9 12 Simplify
4
3
y y
y y
y
y
y
−= +
− = +
− = +
=
=
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Slide P- 53Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 54Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 .
≤
≥
28
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.4
Lines in the Plane
Slide P- 56Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 the fraction.
10 ( 3)
x
x
x x
y
x y
x x y y
− + =
− + + =
− =
− + =
−
− − −
29
Slide P- 57Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
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 (
4
5
)
x
x
x x
y
x
x
x
xy
xy
y
x x y y
− + =
− + + =
− =
− + =
−
− − −
= −
=
−=
−=
−
Slide P- 58Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 why
Linear equations are used extensively in applications involving
business and behavioral science.
30
Slide P- 59Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slope of a Line
Slide P- 60Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
−∆= =
∆ −
=
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Slide P- 61Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Finding the Slope of a Line
Find the slope of the line containing the points (3,-2) and (0,1).
Slide P- 62Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
− − −= = = = −
− − −
−
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Slide P- 63Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 64Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Point-Slope Form of an Equation of a Line
33
Slide P- 65Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 66Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
34
Slide P- 67Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 68Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Viewing Window
35
Slide P- 69Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 70Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
−
+ =
36
Slide P- 71Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 5
Use point-slope form:
43 2
5
x y
y x
y x
y x
+ =
= − +
= − + −
+ = − −
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.5
Solving Equations Graphically,
Numerically, and Algebraically
37
Slide P- 73Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review
( )
( )( )
2
3 2
4 2
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
2to lowest terms.
2 1 1
x y
x x
x x x
y y
x
x x
+
+ −
+ − −
+ −
−+ −
Slide P- 74Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
+
+ −
+ − −
+
+ +
− −
+ − +
+ − +−
( )( )
2
2st terms.
2 1 11
5 2
2 1
xx
x x
x
x x−
+ −
− +
+ −
38
Slide P- 75Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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 why
These basic techniques are involved in using a graphing utility to
solve equations in this textbook.
Slide P- 76Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving by Finding x-Intercepts
2
Solve the equation 2 3 2 0 graphically.x x− − =
39
Slide P- 77Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving by Finding x-Intercepts
2
Solve 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- 78Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Zero Factor Property
Let a and b be real numbers.
If ab = 0, then a = 0 or b = 0.
40
Slide P- 79Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 80Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
+ =
+ + = +
+ = +
41
Slide P- 81Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 82Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving Using the Quadratic
Formula
2
Solve the equation 2 3 5 0.x x+ − =
42
Slide P- 83Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving Using the Quadratic
Formula
2
Solve the equation 2 3 5 0.x x+ − =
( )( )
( )
2
2
2, 3, 5
4
2
3 3 4 2 5
2 2
3 49
4
3 7
4
5 or 1.
2
a b c
b b acx
a
x x
= = = −
− ± −=
− ± − −=
− ±=
− ±=
= − =
Slide P- 84Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
43
Slide P- 85Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 86Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving by Finding Intersections
Solve the equation | 2 1 | 6.x − =
44
Slide P- 87Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
= − =
= − =
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.6
Complex Numbers
45
Slide P- 89Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review
( )( )
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)(3 5)
x x
x x
x x
x x
x x
+ + − +
− − +
+ −
+ −
+ +
Slide P- 90Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
( )( )
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
+ + − +
− − +
+
+
−
+ −
−
+
+ −
+ + +
−
46
Slide P- 91Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 92Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Complex Number
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.
47
Slide P- 93Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 94Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Multiplying Complex Numbers
( )( )Find 3 2 4 .i i+ −
48
Slide P- 95Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 96Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Complex Conjugate
The of the complex number is
.
z a bi
z a bi a bi
= +
= + = −
complex conjugate
49
Slide P- 97Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
+ + =
≠
− >
− =
− <
i
i
i re is a complex pair of solutions.
Slide P- 98Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving a Quadratic Equation
2Solve 2 0.x x+ + =
50
Slide P- 99Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
= = =
− ± −=
− ± −=
− ±=
− + − −= =
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
P.7
Solving Inequalities Algebraically
and Graphically
51
Slide P- 101Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
25. Add the fractions and simplify.
1
x
x
x
x
x
x x
x x
x x
− < + <
+ =
−
−
+
++
+
Slide P- 102Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Quick Review Solutions
( )( )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
x
x
xx
− < <
= − =
−
− < + <
+ =
−
− +
−
+2
2
2
3 22
1
xx
xx x
x
x
+ ++
+ ++
52
Slide P- 103Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
What you’ll learn about
� Solving Absolute Value Inequalities
� Solving Quadratic Inequalities
� Approximating Solutions to Inequalities
� Projectile Motion
… and why
These techniques are involved in using a graphing
utility to solve inequalities in this textbook.
Slide P- 104Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
−∞ − ∞
> < − >
≤ ≥
53
Slide P- 105Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving an Absolute Value
Inequality
Solve | 3 | 5.x + <
Slide P- 106Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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
+ <
− < + <
− < <
−
54
Slide P- 107Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving a Quadratic Inequality
2Solve 3 2 0.x x+ + <
Slide P- 108Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Example Solving a Quadratic Inequality
2Solve 3 2 0.x x+ + <
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
+ + =
+ + =
= − = −
= + +
− −
55
Slide P- 109Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
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- 110Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Chapter Test
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.
3. Find the s
−
lope 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.
2 5 15. Solve the equation algebraically.
3 2 3
6. Solve th
x y
x x
− − −
−
+ =
− ++ =
2e equation algebraically. 6 7 3x x+ =
56
Slide P- 111Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Chapter Test
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 write the result
in standard form. (5 7 ) (3
x
x
x x
i
+ =
+ ≥
+ + ≥
− − − 2 )i