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We begin our review with factoring, which is a necessary skill for addition andsubtraction with fraction notation. Factoring is also an important skill in algebra. You will eventually learn to factor algebraic expressions.
The numbers we will be factoring are natural numbers:
1, 2, 3, 4, 5, and so on.
To factor a number means to express the number as a product. Considerthe product We say that 3 and 4 are factors of 12 and that is afactorization of 12. Since we also know that 12 and 1 are factorsof 12 and that is a factorization of 12.
EXAMPLE 1 Find all the factors of 12.
We first find some factorizations:
The factors of 12 are 1, 2, 3, 4, 6, and 12.
EXAMPLE 2 Find all the factors of 150.
We first find some factorizations:
The factors of 150 are 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75, and 150.
Note that the word “factor” is used both as a noun and as a verb. You factor when you express a number as a product. The numbers you multiplytogether to get the product are factors.
Do Exercises 1–4 (in the margin at left).
PRIME NUMBER
A natural number that has exactly two different factors, itself and 1, iscalled a prime number.
EXAMPLE 3 Which of these numbers are prime? 7, 4, 11, 18, 1
7 is prime. It has exactly two different factors, 1 and 7.
4 is not prime. It has three different factors, 1, 2, and 4.
11 is prime. It has exactly two different factors, 1 and 11.
18 is not prime. It has factors 1, 2, 3, 6, 9, and 18.
1 is not prime. It does not have two different factors.
In the margin at right is a table of the prime numbers from 2 to 157. Thereare more extensive tables, but these prime numbers will be the most helpfulto you in this text.
Do Exercise 5.
If a natural number, other than 1, is not prime, we call it composite. Everycomposite number can be factored into a product of prime numbers. Such afactorization is called a prime factorization.
EXAMPLE 4 Find the prime factorization of 36.
We begin by factoring 36 any way we can. One way is like this:
The factors 4 and 9 are not prime, so we factor them:
The factors in the last factorization are all prime, so we now have the primefactorization of 36. Note that 1 is not part of this factorization because it is not prime.
Another way to find the prime factorization of 36 is like this:
In effect, we begin factoring any way we can think of and keep factoring untilall factors are prime. Using a factor tree might also be helpful.
36
2 18
3 6
2 3
36 � 2 � 3 � 2 � 3
36 � 2 � 18 � 2 � 3 � 6 � 2 � 3 � 2 � 3.
� 2 � 2 � 3 � 3
36 � 4 � 9
36 � 4 � 9.
5. Which of these numbers are prime?
8, 6, 13, 14, 1
Find the prime factorization.
6. 48
7. 50
8. 770
Answers on page A-62
941
APPENDIX A: Factoring and LCMs
or
36
4 9
2 2 3 3
36 � 2 � 2 � 3 � 3
or
36
3 12
2 6
2 3
36 � 3 � 2 � 2 � 3
No matter which way we begin, the result is the same: The prime factori-zation of 36 contains two factors of 2 and two factors of 3. Every compositenumber has a unique prime factorization.
EXAMPLE 5 Find the prime factorization of 60.
This time, we use the list of primes from the table. We go through the tableuntil we find a prime that is a factor of 60. The first such prime is 2.
We keep dividing by 2 until it is not possible to do so.
Now we go to the next prime in the table that is a factor of 60. It is 3.
Each factor in is a prime. Thus this is the prime factorization.
In Example 6, we found common multiples of 2 and 3. The least, or small-est, of those common multiples is 6. We abbreviate least common multipleas LCM.
There are several methods that work well for finding the LCM of severalnumbers. Some of these do not work well in algebra, especially when we consider expressions with variables such as 4ab and 12abc. We now review a method that will work in arithmetic and in algebra as well. To see how it works, let’s look at the prime factorizations of 9 and 15 in order to find the LCM:
Any multiple of 9 must have two 3’s as factors. Any multiple of 15 must haveone 3 and one 5 as factors. The smallest multiple of 9 and 15 is
Two 3’s; 9 is a factor
One 3, one 5; 15 is a factor
The LCM must have all the factors of 9 and all the factors of 15, but the factorsare not repeated when they are common to both numbers.
To find the LCM of several numbers using prime factorizations:
a) Write the prime factorization of each number.b) Form the LCM by writing the product of the different factors from
step (a), using each factor the greatest number of times that itoccurs in any one of the factorizations.
3 � 3 � 5 � 45.
15 � 3 � 5.9 � 3 � 3,
36, . . . .
36 , . . . .
36 , . . . ;
18, . . . .
14 � 2 � 7.
16, . . . .
9. Find the common multiples of 3 and 5 by making lists ofmultiples.
10. Find the common multiples of 9 and 15 by making lists ofmultiples.
b) The different prime factors are 2 and 5. We write 2 as a factor three times(the greatest number of times that it occurs in any one factorization). Wewrite 5 as a factor two times (the greatest number of times that it occurs inany one factorization).
The LCM is or 200.
Do Exercises 11 and 12.
EXAMPLE 8 Find the LCM of 27, 90, and 84.
a) We factor:
b) We write 2 as a factor two times, 3 three times, 5 one time, and 7 one time.
The LCM is or 3780.
Do Exercise 13.
EXAMPLE 9 Find the LCM of 7 and 21.
Since 7 is prime, it has no prime factorization. It still, however, must be afactor of the LCM:
The LCM is or 21.
If one number is a factor of another, then the LCM is the larger of thetwo numbers.
Do Exercises 14 and 15.
EXAMPLE 10 Find the LCM of 8 and 9.
We have
The LCM is or 72.
If two or more numbers have no common prime factor, then the LCMis the product of the numbers.
We now review fraction notation and its use with addition, subtraction,multiplication, and division of arithmetic numbers.
Equivalent Expressions and Fraction Notation
An example of fraction notation for a number is
The top number is called the numerator, and the bottom number is called thedenominator.
The whole numbers consist of the natural numbers and 0:
The arithmetic numbers, also called the nonnegative rational numbers,consist of the whole numbers and the fractions, such as and The arith-metic numbers can also be described as follows.
ARITHMETIC NUMBERS
The arithmetic numbers are the whole numbers and the fractions,such as 8, and All these numbers can be named with fractionnotation where a and b are whole numbers and
Note that all whole numbers can be named with fraction notation. For ex-ample, we can name the whole number 8 as We call 8 and equivalentexpressions.
Being able to find an equivalent expression is critical to a study of algebra.Some simple but powerful properties of numbers that allow us to find equiva-lent expressions are the identity properties of 0 and 1.
THE IDENTITY PROPERTY OF 0(ADDITIVE IDENTITY)
For any number a,
(Adding 0 to any number gives that same number—for example,)
THE IDENTITY PROPERTY OF 1(MULTIPLICATIVE IDENTITY)
For any number a,
Multiplying any number by 1 gives that same number—for example, 35 � 1 � 3
5 .��
a � 1 � a.
12 � 0 � 12.
a � 0 � a.
81
81 .
b � 0.ab ,
65 .3
4 ,
95 .2
3
0, 1, 2, 3, 4, 5, . . . .
23
BB FRACTION NOTATION ObjectivesFind equivalent fractionexpressions by multiplying by 1.
Simplify fraction notation.
Add, subtract, multiply, anddivide using fractionnotation.
The following property allows us to find equivalent fraction expressions, thatis, find other names for arithmetic numbers.
EQUIVALENT EXPRESSIONS FOR 1
For any number a,
We can use the identity property of 1 and the preceding result to findequivalent fraction expressions.
EXAMPLE 1 Write a fraction expression equivalent to with a denomina-tor of 15.
Note that We want fraction notation for that has a denomi-nator of 15, but the denominator 3 is missing a factor of 5. We multiply by 1,using as an equivalent expression for 1. Recall from arithmetic that to mul-tiply with fraction notation, we multiply numerators and denominators:
Using the identity property of 1
Using for 1
Multiplying numerators and denominators
Do Exercises 1–3.
Simplifying Expressions
We know that and so on, all name the same number. Any arithmeticnumber can be named in many ways. The simplest fraction notation is thenotation that has the smallest numerator and denominator. We call theprocess of finding the simplest fraction notation simplifying. We reversethe process of Example 1 by first factoring the numerator and the denomina-tor. Then we factor the fraction expression and remove a factor of 1 using theidentity property of 1.
EXAMPLE 2 Simplify:
Factoring the fraction expression
Using the identity property of 1 (removing a factor of 1) �23
�23
� 1
�23
�55
1015
�2 � 53 � 5
1015
.
48 ,2
4 ,12 ,
�1015
.
55
�23
� 55
23
�23
� 1
55
2315 � 3 � 5.
23
aa
� 1.
a � 0,
55
,33
, and2626
.
Factoring the numerator and the denominator. In thiscase, each is the prime factorization.
1. Write a fraction expressionequivalent to with adenominator of 12.
2. Write a fraction expressionequivalent to with adenominator of 28.
3. Multiply by 1 to find threedifferent fraction expressionsfor
It is always a good idea to check at the end to see if you have indeed fac-tored out all the common factors of the numerator and the denominator.
CANCELINGCanceling is a shortcut that you may have used to remove a factor of 1 whenworking with fraction notation. With great concern, we mention it as a pos-sible way to speed up your work. You should use canceling only when remov-ing common factors in numerators and denominators. Each common factorallows us to remove a factor of 1 in a product. Canceling cannot be donewhen adding. Our concern is that “canceling” be performed with care andunderstanding. Example 3 might have been done faster as follows:
Caution!
The difficulty with canceling is that it is often applied incorrectly insituations like the following:
Wrong! Wrong! Wrong!
The correct answers are
In each situation, the number canceled was not a factor of 1. Factors areparts of products. For example, in 2 and 3 are factors, but in 2and 3 are not factors. Canceling may not be done when sums ordifferences are in numerators or denominators, as shown here.
We can always insert the number 1 as a factor. The identity property of 1allows us to do that.
EXAMPLE 4 Simplify:
or
EXAMPLE 5 Simplify:
Removing a factor of 1:
Simplifying
Do Exercises 7 and 8.
Multiplication, Addition, Subtraction, and Division
After we have performed an operation of multiplication, addition, subtrac-tion, or division, the answer may or may not be in simplified form. We sim-plify, if at all possible.
MULTIPLICATIONTo multiply using fraction notation, we multiply the numerators to get thenew numerator, and we multiply the denominators to get the newdenominator.
MULTIPLYING FRACTIONS
To multiply fractions, multiply the numerators and multiply thedenominators:
EXAMPLE 6 Multiply and simplify:
Multiplying numerators and denominators
Factoring the numerator and the denominator
Removing a factor of 1:
Simplifying
Do Exercises 9 and 10.
�3
10
3 � 53 � 5
� 1 �3 � 5 � 3
3 � 5 � 2 � 5
�5 � 3 � 3
2 � 3 � 5 � 5
56
�9
25�
5 � 96 � 25
56
�9
25.
ab
�cd
�a � cb � d
.
�81
� 8
99
� 1 �8 � 91 � 9
Factoring and inserting a factorof 1 in the denominator
ADDITIONWhen denominators are the same, we can add by adding the numerators andkeeping the same denominator.
ADDING FRACTIONS WITH LIKE DENOMINATORS
To add fractions when denominators are the same, add thenumerators and keep the same denominator:
EXAMPLE 7 Add:
The common denominator is 8. We add the numerators and keep thecommon denominator:
In arithmetic, we generally write as (See a review of converting froma mixed numeral to fraction notation at left.) In algebra, you will find that im-proper fraction symbols such as are more useful and are quite proper for ourpurposes.
What do we do when denominators are different? We find a common de-nominator. We can do this by multiplying by 1. Consider adding and Thereare several common denominators that can be obtained. Let’s look at twopossibilities.
A.
Simplifying �1112
�2224
�4
24�
1824
�16
�44
�34
�66
16
�34
�16
� 1 �34
� 1
34 .1
6
98
1 18 .9
8
48
�58
�4 � 5
8�
98
.
48
�58
.
ac
�bc
�a � b
c.
B.
�1112
�2
12�
912
�16
�22
�34
�33
16
�34
�16
� 1 �34
� 1
We had to simplify in (A). We didn’t have to simplify in (B). In (B), we usedthe least common multiple of the denominators, 12. That number is calledthe least common denominator, or LCD.
ADDING FRACTIONS WITH DIFFERENT DENOMINATORS
To add fractions when denominators are different:
a) Find the least common multiple of the denominators. Thatnumber is the least common denominator, LCD.
b) Multiply by 1, using an appropriate notation, to express eachfraction in terms of the LCD.
c) Add the numerators, keeping the same denominator.d) Simplify, if possible.
n�n,
To convert from a mixednumeral to fraction notation:
The LCM of the denominators, 8 and 12, is 24. Thus the LCD is 24. Wemultiply each fraction by 1 to obtain the LCD:
EXAMPLE 9 Add and simplify:
We first look for the LCM of 30 and 18. That number is then the LCD. Wefind the prime factorization of each denominator:
The LCD is or 90. To get the LCD in the first denominator, we needa factor of 3. To get the LCD in the second denominator, we need a factor of 5.We get these numbers by multiplying by 1:
Multiplying by 1
Simplifying
Do Exercises 11–14.
SUBTRACTIONWhen subtracting, we also multiply by 1 to obtain the LCD. After we havemade the denominators the same, we can subtract by subtracting the numer-ators and keeping the same denominator.
EXAMPLE 10 Subtract and simplify:
The LCD is 40.
�45 � 32
40�
1340
�4540
�3240
98
�45
�98
�55
�45
�88
98
�45
.
�2945
.
�2 � 29
5 � 2 � 3 � 3
�58
5 � 2 � 3 � 3
�33
5 � 2 � 3 � 3�
252 � 3 � 3 � 5
1130
�5
18�
115 � 2 � 3
�33
�5
2 � 3 � 3�
55
5 � 2 � 3 � 3,
1130
�5
18�
115 � 2 � 3
�5
2 � 3 � 3.
1130
�5
18.
�1924
.
�9 � 10
24
�9
24�
1024
38
�5
12�
38
�33
�5
12�
22
38
�5
12.
Multiplying by 1. Since wemultiply the first number by Since
we multiply the secondnumber by 22 .2 � 12 � 24,
33 .
3 � 8 � 24,
Adding the numerators and keeping thesame denominator
The denominators are nowthe LCD.
Adding the numerators andkeeping the LCD
Factoring the numerator andremoving a factor of 1
Subtracting the numerators andkeeping the same denominator
RECIPROCALSTwo numbers whose product is 1 are called reciprocals, or multiplicative inverses, of each other. All the arithmetic numbers, except zero, havereciprocals.
EXAMPLES
12. The reciprocal of is because
13. The reciprocal of 9 is because
14. The reciprocal of is 4 because
Do Exercises 17–20.
RECIPROCALS AND DIVISIONReciprocals and the number 1 can be used to justify a fast way to divide arith-metic numbers. We multiply by 1, carefully choosing the expression for 1.
EXAMPLE 15 Divide by
This is a symbol for 1.
Multiplying numerators and denominators
Simplifying
After multiplying, we had a denominator of or 1. That was because weused the reciprocal of the divisor, for both the numerator and the denomi-nator of the symbol for 1.
When multiplying by 1 to divide, we get a denominator of 1. What do weget in the numerator? In Example 15, we got This is the product of thedividend, and the reciprocal of the divisor.
DIVIDING FRACTIONS
To divide fractions, multiply by the reciprocal of the divisor:
EXAMPLE 16 Divide by multiplying by the reciprocal of the divisor:
is the reciprocal of
Multiplying
After dividing, always simplify if possible.
EXAMPLE 17 Divide and simplify:
is the reciprocal of
Multiplying numerators and denominators
Removing a factor of 1:
Do Exercises 22–24.
EXAMPLE 18 Divide and simplify:
Removing a factor of 1:
EXAMPLE 19 Divide and simplify:
Removing a factor of 1:
Do Exercises 25 and 26.
33
� 1
24 �38
�241
�38
�241
�83
�24 � 81 � 3
�3 � 8 � 8
1 � 3�
8 � 81
� 64
24 �38
.
55
� 1
56
� 30 �56
�301
�56
�1
30�
5 � 16 � 30
�5 � 1
6 � 5 � 6�
16 � 6
�1
36
56
� 30.
�32
2 � 32 � 3
� 1 �2 � 3 � 33 � 2 � 2
�2 � 93 � 4
49
94
23
�49
�23
�94
23
�49
.
�56
35
53
12
�35
�12
�53
12 �
35 .
ab
�cd
�ab
�dc
.
57 ,
23 ,2
3 �57 .
⎫⎪⎪⎬⎪⎪⎭
⎫⎪⎪⎬⎪⎪⎭
Divide by multiplying by thereciprocal of the divisor. Thensimplify.
APPENDIX C: Exponential Notation and Order of Operations
CC EXPONENTIAL NOTATION AND ORDER OF OPERATIONSObjectives
Write exponential notationfor a product.
Evaluate exponentialexpressions.
Simplify expressions usingthe rules for order ofoperations.
Exponential Notation
Exponents provide a shorter way of writing products. An abbreviation for aproduct in which the factors are the same is called a power. For
we write
3 factors
This is read “ten to the third power.” We call the number 3 an exponent andwe say that 10 is the base. An exponent of 2 or greater tells how many timesthe base is used as a factor. For example,
In this case, the exponent is 4 and the base is a. An expression for a power iscalled exponential notation.
This is the exponent.
This is the base.
EXAMPLE 1 Write exponential notation for .
Do Exercises 1–3.
Evaluating Exponential Expressions
EXAMPLE 2 Evaluate:
EXAMPLE 3 Evaluate:
We have
We could also carry out the calculation as follows:
EXPONENTIAL NOTATION
For any natural number n greater than or equal to 2,
What does mean? If we add 4 and 5 and multiply the result by 2, weget 18. If we multiply 5 and 2 and add 4 to the result, we get 14. Since the re-sults are different, we see that the order in which we carry out operations isimportant. To indicate which operation is to be done first, we use groupingsymbols such as parentheses or brackets or braces For example,
but Grouping symbols tell us what to do first. If there are no grouping
symbols, we have agreements about the order in which operations should be done.
RULES FOR ORDER OF OPERATIONS
1. Do all calculations within grouping symbols before operationsoutside.
2. Evaluate all exponential expressions.3. Do all multiplications and divisions in order from left to right.4. Do all additions and subtractions in order from left to right.
EXAMPLE 4 Calculate:
Multiplying
Subtracting
Adding
Do Exercises 7 and 8.
Always calculate within parentheses first. When there are exponents andno parentheses, simplify powers before multiplying or dividing.
CONSTANT TERM POSITIVERecall the FOIL method* of multiplying two binomials:
OFF O I L
I
L
The product is a trinomial. In this example, the leading term has a coefficientof 1. The constant term is positive. To factor we think of FOIL inreverse.
EXAMPLE 1 Factor:
Think of FOIL in reverse. The first term of each factor is x. We are lookingfor numbers p and q such that
We look for two numbers p and q whose product is 8 and whose sum is 9.Since both 8 and 9 are positive, we need consider only positive factors.
The factorization is We can check by multiplying:
Do Exercises 1 and 2.
EXAMPLE 2 Factor:
Since the constant term, 20, is positive and the coefficient of the middleterm, �9, is negative, we look for a factorization of 20 in which both factorsare negative. Their sum must be �9.
Always look first for the largest common factor. This time x is the com-mon factor. We first factor it out:
Now consider Since the constant term, is negative, we lookfor a factorization of in which one factor is positive and one factor is nega-tive. The sum of the factors must be the coefficient of the middle term, sothe negative factor must have the larger absolute value. Thus we consider onlypairs of factors in which the negative factor has the larger absolute value.
The factorization of is But do not forget the com-mon factor! The factorization of the original trinomial is
Do Exercises 5–7.
EXAMPLE 4 Factor:
Since the constant term, �110, is negative, we look for a factorization of�110 in which one factor is positive and one factor is negative. Their summust be 17, so the positive factor must have the larger absolute value.
The factorization is
Do Exercises 8–10.
�x � 5� �x � 22�.
x2 � 17x � 110.
x�x � 5� �x � 6�.
�x � 5� �x � 6�.x2 � x � 30
�1,�30
�30,x2 � x � 30.
x3 � x2 � 30x � x�x2 � x � 30�.
x3 � x2 � 30x.
5. a) Factor
b) Explain why you would notconsider these pairs of factorsin factoring
Factor.
6.
7.
Factor.
8.
9.
10.
Answers on page A-62
x2 � 110 � x
y2 � 4y � 12
x3 � 4x2 � 12x
2x3 � 2x2 � 84x
x3 � 3x2 � 54x
x2 � x � 20.
x2 � x � 20.
960
APPENDIX D: Review of Factoring Polynomials
1, �30 �29
2, �15 �13
3, �10 �7
5, �6 �1
PAIRS OF FACTORS SUMS OF FACTORS
The numbers we want are5 and �6.
�1, 110 109
�2, 55 53
�5, 22 17
�10, 11 1
PAIRS OF FACTORS SUMS OF FACTORS
The numbers we need are�5 and 22.
We consider only pairs of factorsin which the positive term hasthe larger absolute value.
We consider the FOIL method for factoring trinomials of the type
, .
Consider the following multiplication.
F O I L
To factor , we must reverse what we just did. We look for twobinomials whose product is this trinomial. The product of the First termsmust be . The product of the Outside terms plus the product of the Insideterms must be 23x. The product of the Last terms must be 10. We know fromthe preceding discussion that the answer is . In general,however, finding such an answer involves trial and error. We use the follow-ing method.
THE FOIL METHOD
To factor trinomials of the type using the FOILmethod:
1. Factor out the largest common factor.2. Find two First terms whose product is :
FOIL
3. Find two Last terms whose product is c:
FOIL
4. Repeat steps (2) and (3) until a combination is found for which thesum of the Outside and Inside products is bx :
I FOILO
5. Always check by multiplying.
EXAMPLE 5 Factor: .
1. First, we factor out the largest common factor, if any. There is none (otherthan 1 or �1).
2. Next, we factor the first term, . The only possibility is . The desired factorization is then of the form .
3. We then factor the last term, �8, which is negative. The possibilities are, , , and . They can be written in either order.��2� �4�2��4�8��1���8� �1�
4. We look for combinations of factors from steps (2) and (3) such that thesum of the outside and the inside products is the middle term, 10x :
3x
;
�8x Wrong middle term
�12x
;
2x Wrong middle term
�3x � 2� �x � 4� � 3x2 � 10x � 8
�3x � 8� �x � 1� � 3x2 � 5x � 8
Factor by the FOIL method.
11.
12.
Answers on page A-62
3x2 � 5x � 2
3x2 � 13x � 56
962
APPENDIX D: Review of Factoring Polynomials
�3x
;
8x Wrong middle term
12x
�2x Correct middle term!
�3x � 2� �x � 4� � 3x2 � 10x � 8
�3x � 8� �x � 1� � 3x2 � 5x � 8
There are four other possibilities that we could try, but we have a fac-torization: .
5. Check : .
Do Exercises 11 and 12.
EXAMPLE 6 Factor: .
1. First, we factor out the largest common factor, if any. The expression is common to all terms, so we factor it out: .
2. Next, we factor the trinomial . We factor the first term, , and get or We then have these as possibilities for fac-
torizations: or .
3. We then factor the last term, 10, which is positive. The possibilities areand They can be written in either
order.
4. We look for combinations of factors from steps (2) and (3) such that thesum of the outside and the inside products is the middle term, �19x. Thesign of the middle term is negative, but the sign of the last term, 10, ispositive. Thus the signs of both factors of the last term, 10, must be nega-tive. From our list of factors in step (3), we can use only �10, �1 and �5,�2 as possibilities. This reduces the possibilities for factorizations byhalf. We begin by using these factors with . Should wenot find the correct factorization, we will consider .
�3x
;
�20x Wrong middle term
�6x
;
�10x Wrong middle term
�3x � 5� �2x � 2� � 6x2 � 16x � 10
�3x � 10� �2x � 1� � 6x2 � 23x � 10
�� �x ��6x �
�� �2x ��3x �
��5� ��2�.�5� �2�,��10� ��1�,�10� �1�,
�� �x ��6x ��� �2x ��3x �
3x � 2x.6x � x,6x26x2 � 19x � 10
3x4�6x2 � 19x � 10�3x4
18x6 � 57x5 � 30x4
�3x � 2� �x � 4� � 3x2 � 10x � 8
�3x � 2� �x � 4�
�30x
;
�2x Wrong middle term
�15x
�4x Correct middle term!
�3x � 2� �2x � 5� � 6x2 � 19x � 10
�3x � 1� �2x � 10� � 6x2 � 32x � 10
We have a correct answer. We need not consider .The factorization of is . But do not
forget the common factor! We must include it in order to get a completefactorization of the original trinomial:
Next, we consider some special factoring methods. When we recognizecertain types of polynomials, we can factor more quickly using these spe-cial methods. Most of them are the reverse of the methods of special multiplication.
Trinomial Squares
Consider the trinomial . We look for factors of 9 whose sum is 6.We see that these factors are 3 and 3 and the factorization is
.
Note that the result is the square of a binomial. We also call a trinomial square, or perfect-square trinomial.
The factors of a trinomial square are two identical binomials. We use thefollowing equations.
TRINOMIAL SQUARES
;
EXAMPLE 7 Factor: .
We find the square terms and write their square roots with a minus signbetween them.Note the sign!
EXAMPLE 8 Factor: .
Rewriting in descending order
We find the square terms andwrite their square roots with aplus sign between them.
Do Exercises 15 and 16.
Differences of Squares
The following are differences of squares:
, , .
To factor a difference of two expressions that are squares, we can use a patternfor multiplying a sum and a difference that we used earlier.
To factor a difference of two squares, write the square root of the firstexpression plus the square root of the second times the square root ofthe first minus the square root of the second.
EXAMPLE 9 Factor: .
EXAMPLE 10 Factor: .
Do Exercises 17 and 18.
Sums or Differences of Cubes
We can factor the sum or the difference of two expressions that are cubes.Consider the following products:
and
.
The above equations (reversed) show how we can factor a sum or a differenceof two cubes.
SUM OR DIFFERENCE OF CUBES
;
Note that what we are considering here is a sum or a difference of cubes. We are not cubing a binomial. For example, is not the same as . The table of cubes in the margin is helpful.
EXAMPLE 11 Factor: .
We have
.
In one set of parentheses, we write the cube root of the first term, x. Then we write the cube root of the second term, �10. This gives us the expres-sion
This text is appropriate for a two-semester course that combines thestudy of introductory and intermediate algebra. Students who take only thesecond-semester course (which generally begins with Chapter 7) often need areview of the topics covered in the first-semester course. This appendix is aguide for a review of the first six chapters of this text. Below is a syllabus ofselected exercises that can be used as a condensed review of the main objec-tives in the first half of the text. For extra help, consult the Student’s SolutionsManual, which contains fully worked-out solutions with step-by-step anno-tations for all the odd-numbered exercises in the exercise sets.
EE INTRODUCTORY ALGEBRA REVIEW
1.3a 5–13 3, 11, 19, 25, 33, 39, 43
1.4a 6–12 5, 9, 15, 19, 21, 51, 55, 69, 81
1.5a 4–12, 17 17, 29, 33, 39, 53, 69
1.6c 19–23 49, 53, 55, 57
1.7c 14–17 47, 49, 59
1.7d 28– 31 73, 81, 83
1.7e 32–38 89, 97, 101, 107
1.8b 7, 11, 12 15, 21
1.8c 16 29, 35
1.8d 20–23 41, 51, 61, 81
2.1b 6, 7 19, 39, 47
2.2a 2, 3, 6 3, 7, 27, 33
2.3a 2 5, 15
2.3b 7, 9 23, 43, 51
2.3c 11, 12, 13 71, 73, 83, 87
2.5a 4, 5, 6, 8 7, 15, 25, 35
2.6a 1, 2, 5, 8 1, 7, 15, 27
2.7e 13, 16 53, 61, 75
3.2a 2, 3, 5 5, 13, 21
3.3a 1 21, 25
3.3b 3, 4 45, 51
3.4a 1 9, 11
3.4c 5, 9, 10, 11 37, 51, 55
4.1b 2 15, 17
4.1c 5, 6 27, 35
4.1d, e, f 8, 11, 13, 15, 22–27 67, 71, 83, 91, 95, 103
4.2a, b 1–4, 10, 15, 16 3, 35, 41, 45
4.4a 3, 4 7, 17
4.4c 9, 10 33, 41, 49
4.5d 10 55
4.6a 2–6 9, 29
4.6b 11–13 43, 47
4.6c 16–18 63, 67, 71
4.7c 4–6 21, 27
4.7f 11, 12 41, 57
4.8b 7, 8, 10 25, 29, 33, 39
SECTION/OBJECTIVE EXAMPLES EXERCISES IN EXERCISE SET
Two other features of the text that can be used for review of the first sixchapters are as follows.
• At the end of each chapter is a Summary and Review that provides an ex-tensive set of review exercises. Reference codes beside each exercise or di-rection line preceding it allow the student to easily return to the objectivebeing reviewed. Answers to all of these exercises appear at the back ofthe book.
• The Cumulative Review that follows both Chapter 3 and Chapter 6 canalso be used for review. Each reviews material from all preceding chap-ters. At the back of the text are answers to all Cumulative Review exer-cises, together with section and objective references, so that studentsknow exactly what material to study if they miss an exercise.
The extensive supplements package that accompanies this text alsoincludes material appropriate for a structured review of the first six chapters.Consult the preface in the text for detailed descriptions of each of thefollowing.
• Videotapes and Digital Video Tutor
• Work It Out! Chapter Test Video on CD
• MathXL® Tutorials on CD
• MathXL®
• MyMathLab
969
APPENDIX E: Introductory Algebra Review
5.1b 9–12 19, 27
5.1c 13, 15, 18 39, 47
5.2a 1, 2, 3 1, 21, 27
5.3a 1, 2 3, 11, 25, 39, 71
5.4a 1 19, 35
5.5b 4, 6 13, 19, 29
5.5d 13, 17, 19 51, 55, 63, 77
5.6a 1, 2 1, 9, 23, 27
5.8b 4 25, 29, 37
5.9b 6 25
6.1d 11, 12 57, 59
6.2b 6, 8 13, 31
6.3c 4, 6 25, 31
6.4a 5, 6, 8 11, 17, 27, 59
6.5a 3, 4 9, 17, 39
6.7a 1, 3, 5 5, 11, 21, 35
6.8a 2 13
6.8b 3 27
SECTION/OBJECTIVE EXAMPLES EXERCISES IN EXERCISE SET
In many applications, we add, subtract, multiply, and divide quantitieshaving units, or dimensions, such as ft, km, sec, and hr. For example, to findaverage speed, we divide total distance by total time. What results is nota-tion very much like a rational expression.
EXAMPLE 1 A car travels 150 km in 2 hr. What is its average speed?
, or
(The standard abbreviation for is , but it does not suit our pres-ent discussion well.)
The symbol makes it look as though we are dividing kilometersby hours. It can be argued that we can divide only numbers. Nevertheless, wetreat dimension symbols, such as km, ft, and hr, as if they were numerals orvariables, obtaining correct results mechanically.
Do Exercise 1.
EXAMPLES Compare the following.
2. with
3. with
4. with (square feet)
Do Exercises 2–4.
If 5 men work 8 hours, the total amount of labor is 40 man-hours.
EXAMPLE 5 Compare
with .
Do Exercise 5.
5 men � 8 hours � 40 man-hours5x � 8y � 40xy
5 ft � 3 ft � 15 ft25x � 3x � 15x2
3 ft � 2 ft � �3 � 2� ft � 5 ft3x � 2x � �3 � 2�x � 5x
150 km2 hr
�150
2kmhr
� 75kmhr
150x2y
�150
2�
xy
� 75xy
km�hr
km�hkm�hr
75kmhr
Speed �150 km
2 hr
FF HANDLING DIMENSION SYMBOLS
1. A truck travels 210 mi in 3 hr.What is its average speed?
If an electrical device uses 300 kW (kilowatts) for 240 hr over a period of 15 days, its rate of usage of energy is 4800 kilowatt-hours per day. The standard abbreviation for kilowatt-hours is kWh.
Do Exercise 6.
Making Unit Changes
We can treat dimension symbols much like numerals or variables, becausewe obtain correct results that way. We can change units by substituting or bymultiplying by 1, as shown below.
EXAMPLE 7 Convert 3 ft to inches.
METHOD 1. We have 3 ft. We know that , so we substitute 12 in.for ft:
METHOD 2. We want to convert from “ft” to “in.” We multiply by 1 using asymbol for 1 with “ft” on the bottom since we are converting from “ft,” andwith “in.” on the top since we are converting to “in.”
Do Exercise 7.
We can multiply by 1 several times to make successive conversions. In thefollowing example, we convert to by converting successivelyfrom to to to .
One way to analyze data is to look for a single representative number, called acenter point or measure of central tendency. Those most often used are themean (or average), the median, and the mode.
MEANLet’s first consider the mean, or average.
MEAN, OR AVERAGE
The mean, or average, of a set of numbers is the sum of the numbersdivided by the number of addends.
EXAMPLE 1 Consider the following data on total net revenue, inbillions of dollars, for Starbucks Corporation for the years 2000–2004:
$2.2, $2.6, $3.3, $4.1, $5.3
What is the mean of the numbers?Source: Starbucks Corporation
First we add the numbers:
Then we divide by the number of addends, 5:
The mean, or average, revenue of Starbucks for those five years is $3.5 billion.
Note that If we use this cen-ter point, 3.5, repeatedly as the addend, we get the same sum that wedo when adding the individual data numbers.
Do Exercises 1–3.
MEDIANThe median is useful when we wish to de-emphasize extreme values. For example, suppose five workers in a technology company manufactured thefollowing number of computers during one day’s work:
Sarah: 88 Jen: 94
Matt: 92 Mark: 91
Pat: 66
Let’s first list the values in order from smallest to largest:
66 88 91 92 94.
Middle number
The middle number—in this case, 91—is the median.
3.5 � 3.5 � 3.5 � 3.5 � 3.5 � 17.5.
�2.2 � 2.6 � 3.3 � 4.1 � 5.3�5
�17.5
5� 3.5.
2.2 � 2.6 � 3.3 � 4.1 � 5.3 � 17.5.
GG MEAN, MEDIAN, AND MODEObjectiveFind the mean (average), themedian, and the mode of aset of data and solve relatedapplied problems.
Once a set of data has been arranged from smallest to largest, themedian of the set of data is the middle number if there is an oddnumber of data numbers. If there is an even number of datanumbers, then there are two middle numbers and the median is the average of the two middle numbers.
EXAMPLE 2 What is the median of the following set of yearly salaries?
There is an even number of numbers. We look for the middle two, which are $62,500 and $64,800. In this case, the median is the average of $62,500 and $64,800:
Do Exercises 4–6.
MODEThe last center point we consider is called the mode. A number that occursmost often in a set of data can be considered a representative number or center point.
MODE
The mode of a set of data is the number or numbers that occur mostoften. If each number occurs the same number of times, there is no mode.
EXAMPLE 3 Find the mode of the following data:
23, 24, 27, 18, 19, 27
The number that occurs most often is 27. Thus the mode is 27.
EXAMPLE 4 Find the mode of the following data:
83, 84, 84, 84, 85, 86, 87, 87, 87, 88, 89, 90.
There are two numbers that occur most often, 84 and 87. Thus the modesare 84 and 87.
EXAMPLE 5 Find the mode of the following data:
115, 117, 211, 213, 219.
Each number occurs the same number of times. The set of data has no mode.
Do Exercises 7–10.
$62,500 � $64,8002
� $63,650.
Find the median.
4. 17, 13, 18, 14, 19
5. 17, 18, 16, 19, 13, 14
6. 122, 102, 103, 91, 83, 81, 78,119, 88
Find any modes that exist.
7. 33, 55, 55, 88, 55
8. 90, 54, 88, 87, 87, 54
9. 23.7, 27.5, 54.9, 17.2, 20.1
10. In conducting laboratory tests,Carole discovers bacteria indifferent lab dishes grew to the following areas, in squaremillimeters:
9. Atlantic Storms and Hurricanes. The following bargraph shows the number of Atlantic storms orhurricanes that formed in various months from 1980 to 2000. What is the average number for the 9 monthsgiven? the median? the mode?
10. Cheddar Cheese Prices. The following prices per pound of sharp cheddar cheese were found at fivesupermarkets:
$5.99, $6.79, $5.99, $6.99, $6.79.
What was the average price per pound? the medianprice? the mode?
11
25
60
72
29
15
1 1 1
June July Aug. Sept. Oct. Nov.April May Dec.July Aug. Sept. Oct. Nov.April May Dec.
Source: Colorado State University
Atlantic Storms and HurricanesTropical storm and hurricane formation in 1980–2000, by month
June July Aug. Sept. Oct. Nov.April May Dec.
11. Coffee Consumption. The following lists the annualcoffee consumption, in cups per person, for variouscountries. Find the mean, the median, and the mode.
Germany 1113
United States 610
Switzerland 1215
France 798
Italy 750Source: Beverage Marketing Corporation
12. NBA Tall Men. The following is a list of the heights, ininches, of the tallest men in the NBA in a recent year.Find the mean, the median, and the mode.
Shaquille O’Neal 85
Gheorghe Muresan 91
Shawn Bradley 90
Priest Lauderdale 88
Rik Smits 88
David Robinson 85
Arvydas Sabonis 87Source: National Basketball Association
To divide a polynomial by a binomial of the type we can streamline thegeneral procedure by a process called synthetic division.
Compare the following. In A, we perform a division. In B, we also dividebut we do not write the variables.
A.
29
11x � 22 11x � 7
5x2 � 10x 5x2 � x
4x3 � 8x2 x � 2�4x3 � 3x2 � x � 7
4x2 � 5x � 11
x � a,
HH SYNTHETIC DIVISIONObjectiveUse synthetic division todivide a polynomial by abinomial of the type
.x � a
B.
29
11 � 22 11 � 7
5 � 10 5 � 1
4 � 8 1 � 2�4 � 3 � 1 � 7
4 � 5 � 11
In B, there is still some duplication of writing. Also, since we can subtractby adding the opposite, we can use 2 instead of �2 and then add instead ofsubtracting.
C. Synthetic Division
a) Write the 2, the opposite of �2 in the divisor and the coefficients of the dividend.
Bring down the first coefficient.
b)Multiply 4 by 2 to get 8. Add 8 and �3.
c)Multiply 5 by 2 to get 10. Add 10 and 1.
d)Multiply 11 by 2 to get 22. Add 22 and 7.
Quotient Remainder
The last number, 29, is the remainder. The other numbers are the coefficientsof the quotient with that of the term of highest degree first, as follows. Notethat the degree of the term of highest degree is 1 less than the degree of thedividend.
When there are missing terms, be sure to write 0’s for their coefficients.
EXAMPLES Use synthetic division to divide.
2.
There is no x-term, so we must write a 0 for its coefficient. Note thatso we write �3 at the left.
The answer is R 4; or
3.
Note that so we write �4 at the left.
The answer is
4.
The divisor is so we write 1 at the left.
The answer is
5.
Note that so we write �2 at the left.
The answer is R �218; or
Do Exercises 2 and 3.
8x4 � 16x3 � 26x2 � 52x � 105 ��218x � 2
.
8x4 � 16x3 � 26x2 � 52x � 105,
8 �16 26 �52 105 �218
�16 32 �52 104 �210 �2 �8 0 �6 0 1 �8
x � 2 � x � ��2�,�8x5 � 6x3 � x � 8� � �x � 2�
x3 � x2 � x � 1.
1 1 1 1 0
1 1 1 1 1 �1 0 0 0 �1
x � 1,
�x4 � 1� � �x � 1�
x2 � 1.
1 0 �1 0
�4 0 4 �4 �1 4 �1 �4
x � 4 � x � ��4�,�x3 � 4x2 � x � 4� � �x � 4�
2x2 � x � 3 �4
x � 3.2x2 � x � 3,
2 1 �3 4
�6 �3 9 �3 �2 7 0 �5
x � 3 � x � ��3�,
�2x3 � 7x2 � 5� � �x � 3�
x2 � 8x � 15.x2 � 8x � 15,
1 8 15 0
2 16 30
2 �1 6 �1 �30
�x3 � 6x2 � x � 30� � �x � 2�.
4x2 � 5x � 11 �29
x � 2.4x2 � 5x � 11,
1. Use synthetic division to divide:
Use synthetic division to divide.
2.
3.
Answers on page A-63
� y3 � 1� � � y � 1�
�x3 � 2x2 � 5x � 4� � �x � 2�
�2x3 � 4x2 � 8x � 8� � �x � 3�.
977
APPENDIX H: Synthetic Division
It is important to rememberthat in order for syntheticdivision to work, the divisormust be of the form thatis, a variable minus a constant.The coefficient of the variablemust be 1.
In Chapter 8, you probably noticed that the elimination method concernsitself primarily with the coefficients and constants of the equations. Here welearn a method for solving a system of equations using just the coefficientsand constants. This method involves determinants.
Evaluating Determinants
The following symbolism represents a second-order determinant:
.
To evaluate a determinant, we do two multiplications and subtract.
EXAMPLE 1 Evaluate:
.
We multiply and subtract as follows:
.
Determinants are defined according to the pattern shown in Example 1.
SECOND-ORDER DETERMINANT
The determinant is defined to mean .
The value of a determinant is a number. In Example 1, the value is 44.
Note that the second-order determinants on the right can be obtained bycrossing out the row and the column in which each a occurs.
For : For :
For :
EXAMPLE 2 Evaluate this third-order determinant:
.
We calculate as follows:
.
Do Exercises 3 and 4.
Solving Systems Using Determinants
Here is a system of two equations in two variables:
,
.
We form three determinants, which we call D, , and .
In D, we have the coefficients of x and y.
To form , we replace the x-coefficients in Dwith the constants on the right side of theequations.
To form , we replace the y-coefficients in Dwith the constants on the right.
It is important that the replacement be done without changing the order of thecolumns. Then the solution of the system can be found as follows. This isknown as Cramer’s rule.
Cramer’s rule for three equations is very similar to that for two.
D is again the determinant of the coefficients of x, y, and z. This time we haveone more determinant, . We get it by replacing the z-coefficients in D withthe constants on the right:
In Example 4, we would not have needed to evaluate . Once we foundx and y, we could have substituted them into one of the equations to find z.In practice, it is faster to use determinants to find only two of the numbers;then we find the third by substitution into an equation.
Do Exercise 6.
In using Cramer’s rule, we divide by D. If D were 0, we could not do so.
INCONSISTENT SYSTEMS;DEPENDENT EQUATIONS
If and at least one of the other determinants is not 0, then thesystem does not have a solution, and we say that it is inconsistent.
If and all the other determinants are also 0, then there is aninfinite set of solutions. In that case, we say that the equations in the system are dependent.
The elimination method concerns itself primarily with the coefficientsand constants of the equations. In what follows, we learn a method for solv-ing systems using just the coefficients and the constants. This procedure in-volves what are called matrices.
In solving systems of equations, we perform computations with theconstants. The variables play no important role until the end. Thus we cansimplify writing a system by omitting the variables. For example, the system
,
x � 2y � 1
3x � 4y � 5
JJ ELIMINATION USING MATRICESObjectiveSolve systems of two or threeequations using matrices.
simplifies to
if we omit the variables, the operation of addition, and the equals signs. Theresult is a rectangular array of numbers. Such an array is called a matrix(plural, matrices). We ordinarily write brackets around matrices. The follow-ing are matrices.
The rows of a matrix are horizontal, and the columns are vertical.
column 1 column 2 column 3
Let’s now use matrices to solve systems of linear equations.
EXAMPLE 1 Solve the system
We write a matrix using only the coefficients and the constants, keepingin mind that x corresponds to the first column and y to the second. A dashedline separates the coefficients from the constants at the end of each equation:
The individual numbers are called elements or entries.
Our goal is to transform this matrix into one of the form
The variables can then be reinserted to form equations from which we cancomplete the solution.
We do calculations that are similar to those that we would do if we wrotethe entire equations. The first step, if possible, is to multiply and/or inter-change the rows so that each number in the first column below the first num-ber is a multiple of that number. In this case, we do so by multiplying Row 2by 5. This corresponds to multiplying the second equation by 5.
New Row (Row 2)
Next, we multiply the first row by 2 and add the result to the second row. Thiscorresponds to multiplying the first equation by 2 and adding the result to thesecond equation. Although we write the calculations out here, we generallytry to do them mentally:
New Row
If we now reinsert the variables, we have
(1)
(2)
We can now proceed as before, solving equation (2) for y:
(2)
Next, we substitute for y back in equation (1). This procedure is called back-substitution.
(1)
Substituting for y in equation (1)
Solving for x
The solution is
Do Exercise 1.
EXAMPLE 2 Solve the system
We first write a matrix, using only the coefficients and the constants.Where there are missing terms, we must write 0’s:
.
Our goal is to find an equivalent matrix of the form
A matrix of this form can be rewritten as a system of equations from which asolution can be found easily.
�a00
be0
cf
h
dgi�.
(P1), (P2), and (P3) designate theequations that are in the first,second, and third position,respectively.
The first step, if possible, is to interchange the rows so that each numberin the first column below the first number is a multiple of that number. In thiscase, we do so by interchanging Rows 1 and 2:
.
Next, we multiply the first row by �2 and add it to the second row:
Now we multiply the first row by �6 and add it to the third row:
Next, we multiply Row 2 by �1 and add it to the third row:
Reinserting the variables gives us
(P1)
(P2)
(P3)
We now solve (P3) for z:
(P3)
Solving for z
Next, we back-substitute for z in (P2) and solve for y :
(P2)
Substituting for z in equation (P2)
Solving for y
Since there is no y-term in (P1), we need only substitute for z in (P1) andsolve for x:
(P1)
Substituting for z in equation (P1)
Solving for x
The solution is
Do Exercise 2.
�3, 7, �12�.
x � 3.
x � 2 � 5
�12 x � 4��
12� � 5
x � 4z � 5
�12
y � 7.
�y � �7
�y � 6 � �13
�12 �y � 12��
12� � �13
�y � 12z � �13
�12
z � �12 .
z � �7
14
14z � �7
14z � �7.
�y � 12z � �13,
x � 4z � 5,
This corresponds to multiplying equation(P2) by �1 and adding it to equation (P3).�1
00
0�1
0
�41214
5�13
�7�.
This corresponds to multiplying equation(P1) by �6 and adding it to equation (P3).�1
00
0�1�1
�41226
5�13�20
�.
This corresponds to multiplying newequation (P1) by �2 and adding it to newequation (P2). The result replaces theformer (P2). We perform the calculationsmentally.
�106
0�1�1
�412
2
5�13
10�.
This corresponds to interchangingthe first two equations.�1
All the operations used in the preceding example correspond to opera-tions with the equations and produce equivalent systems of equations. Wecall the matrices row-equivalent and the operations that produce them row-equivalent operations.
ROW-EQUIVALENT OPERATIONS
Each of the following row-equivalent operations produces anequivalent matrix:
a) Interchanging any two rows.b) Multiplying each element of a row by the same nonzero number.c) Multiplying each element of a row by a nonzero number and
adding the result to another row.
The best overall method of solving systems of equations is by row-equivalent matrices; graphing calculators and computers are programmedto use them. Matrices are part of a branch of mathematics known as linearalgebra. They are also studied in more detail in many courses in finitemathematics.
In carpentry, surveying, engineering, and other fields, it is often neces-sary to determine distances and midpoints and to produce accurately drawn circles.
The Distance Formula
Suppose that two points are on a horizontal line, and thus have the same sec-ond coordinate. We can find the distance between them by subtracting theirfirst coordinates. This difference may be negative, depending on the order inwhich we subtract. So, to make sure we get a positive number, we take the ab-solute value of this difference. The distance between two points on a horizon-tal line and is thus Similarly, the distance betweentwo points on a vertical line and is
Now consider any two points and If and these points are vertices of a right triangle, as shown. The other vertex is then
The lengths of the legs are and We find d, thelength of the hypotenuse, by using the Pythagorean theorem:
Since the square of a number is the same as the square of its opposite, wedon’t need these absolute-value signs. Thus,
Taking the principal square root, we obtain the distance between two points.
THE DISTANCE FORMULA
The distance between any two points and is given by
This formula holds even when the two points are on a vertical or a hori-zontal line.
ObjectivesUse the distance formula tofind the distance betweentwo points whosecoordinates are known.
Use the midpoint formula tofind the midpoint of asegment when thecoordinates of its endpointsare known.
Given an equation of a circle,find its center and radiusand graph it; and given thecenter and radius of a circle,write an equation of thecircle and graph the circle.
Another conic section, or curve, shown in the figure at the beginning of thissection is a circle. A circle is defined as the set of all points in a plane that area fixed distance from a point in that plane.
Let’s find an equation for a circle. We call the center and let the ra-dius have length r. Suppose that is any point on the circle. By the dis-tance formula, we have
Squaring both sides gives an equation of the circle in standard form:When and the circle is centered at the
origin. Otherwise, we can think of that circle being translated units hori-zontally and units vertically from the origin.
EQUATIONS OF CIRCLES
A circle centered at the origin with radius r has equation
A circle with center and radius r has equation
(Standard form)
EXAMPLE 3 Find the center and the radius and graph this circle:
First, we find an equivalent equation in standard form:
Thus the center is and theradius is 4. We draw the graph,shown at right, by locating thecenter and then using a compass,setting its radius at 4, to drawthe circle.
EXAMPLE 4 Write an equation of a circle with center and radius
We use standard form and substitute:
Substituting
Simplifying
Do Exercise 7.
With certain equations not in standard form, we can complete the squareto show that the equations are equations of circles. We proceed in much thesame manner as we did in Section 11.6.
EXAMPLE 5 Find the center and the radius and graph this circle:
First, we regroup the terms and then complete the square twice, oncewith and once with
32. 33.34. Associative law of multiplication35. Identity property of 136. Commutative law of addition37. Distributive law of multiplication over addition38. Identity property of 039. Commutative law of multiplication40. Associative law of addition41. 42. 43.
31. �2 32. 2 33. �9 34. 8-yd gain 35. �$13036. $4.64 37. $18.95 38. 39.40. 41. 42.43. or 44.45. or 46.47. 48. 49. 50.51. 52. 6 53. 54.55. 56. True 57. False 58.59. If the sum of two numbers is 0, they are opposites, or additive inverses of each other. For every real number a, the opposite of a can be named �a, and
1. 3. 5.7. 9. 11. 13.15. 17. 19.21. 23. 25.27. 29. 15 or fewer copies 31. 5 min ormore 33. 2 courses 35. 4 servings or more37. Lengths greater than or equal to 92 ft; lengths less thanor equal to 92 ft 39. Lengths less than 21.5 cm41. The blue-book value is greater than or equal to $10,625.43. It has at least 16 g of fat. 45. Dates at least 6 weeksafter July 1 47. Heights greater than or equal to 4 ft49. 21 calls or more 51. 53. Even 54. Odd55. Additive 56. Multiplicative 57. Equivalent58. Addition principle 59. Multiplication principle; is reversed 60. Solution61. Temperatures between and 63. They contain at least 7.5 g of fat per serving.
n � �2w � 110d � 1545 � t � 55p � 21,900c � 4000m � 92
37x � 1�2x � 23�9.4�
78�38
�1.11�58�74DW
�x � x � �2��x x � �5734��r � r � �3�
�t t � �53��m � m � 6�� y � y � 6�
� y � y � �3��x � x � 9��x � x � �4�� y � y � �2�� y � y � 3�� y � y � 2�
34. 35.
0
�2 � x 5
�2 50
x � 3
3
36. 37. 38.
39. 40. 41. Length: 365 mi;
width: 275 mi 42. 345, 346 43. $211744. 27 appliances 45. 46. 1547. 18.75% 48. 600 49. About 26% 50. $22051. $53,400 52. $138.95 53. 86 54.55. The end result is the same either way. If is theoriginal salary, the new salary after a 5% raise followed by an8% raise is . If the raises occur the other wayaround, the new salary is . By the commutativeand associative laws of multiplication, we see that these areequal. However, it would be better to receive the 8% raisefirst, because this increase yields a higher salary initiallythan a 5% raise. 56. The inequalities are equivalentby the multiplication principle for inequalities. If wemultiply both sides of one inequality by the otherinequality results. 57. 23, 58. 20,
3. 4. 4.5 cents per minute5. �1700 deaths by firearms per year 6. 4 7. �178. �1 9. 10. �1 11. 12. Not defined 13. 0
Calculator Corner, p. 203
1. This line will pass through the origin and slant up fromleft to right. This line will be steeper than 2. This line will pass through the origin and slant up fromleft to right. This line will be less steep than
Calculator Corner, p. 204
1. This line will pass through the origin and slant downfrom left to right. This line will be steeper than 2. This line will pass through the origin and slant downfrom left to right. This line will be less steep than
17. 19. Not defined 21. 23. 0 25.27. 29. About 29.4% 31. 25 miles per gallon33. �$500 per year 35. About 7600 people per year37. �10 39. 3.78 41. 3 43. 45.47. Not defined 49. �2.74 51. 3 53. 55. 0
22. (a) 2.4 driveways per hour; (b) 25 minutes per driveway23. 4 manicures per hour 24. 25.
26. 27.
28. 7% 29. 30. 31. Not defined 32. 0
33. The y-intercept is the point at which the graphcrosses the y-axis. Since a point on the y-axis is neither leftnor right of the origin, the first or x-coordinate of the pointis 0. 34. The x-intercept is the point at which thegraph crosses the x-axis. Since a point on the x-axis isneither up nor down from the origin, the second coordinateof the point is 0. 35. 36. 45 square units; 28 linear units 37. (a) 3.709 feet per minute; (b) about0.2696 minute per foot
Test: Chapter 3, p. 214
1. [3.1a] II 2. [3.1a] III 3. [3.1b] 4. [3.1b] 5. [3.1c]
16. 17. 689,300,000,000 18. 0.000056719. 20. 21.22. 23.24. The mass of Saturn is times the mass of Earth.
Calculator Corner, p. 237
1. 2. 3.4. 5. 6. 7.8.
Exercise Set 4.2, p. 240
1. 3. 5. 7. 9. 11.
13. 15. 17. 19. 21.
23. 25. 27. 29. 31.
33. 35. 37. 39. 41.
43. 45. 47. 49. 51.
53. 55. 57.59. 61. 63. 65.67. 87,400,000 69. 0.00000005704 71. 10,000,00073. 0.00001 75. 77.79. 81. 83.85. 87. Approximately 89. The mass of Jupiter is times the mass of Earth.91. 93. The mass of the sun is times the mass of Earth. 95. days 97.99. 100. 101.102. 103. 104. 2 105. 106.107.
1. ; ; ; answers may vary2. 3. 4. 5. 21 6. 6; 7. 132 games 8. 360 ft 9. (a) 7.55 parts per million;(b) When , ; so the value found in part (a)appears to be correct. 10. 20 parts per million11. 12.13. , , 14. , , , 15. and 16. and ; and 17. and ; and
1. 2. 3.4. 5.6. 7. 8.9. 10.11. 12.13. 14. 15. 16.17. 18. 19.20. 21. 22.23. 24.25. 26.27. 28. represents the area of the large square. This includes all four sections. represents only two of the sections. 29.30. 31.32. 33.34. 35.36.
Visualizing for Success, p. 280
1. E, F 2. B, O 3. S, K 4. R, G 5. D, M 6. J, P7. C, L 8. N, Q 9. A, H 10. I, T
52. is not in scientific notation because 578.6 is larger than 10. 53. A monomial is an expression of the type , where n is a whole number anda is a real number. A binomial is a sum of two monomialsand has two terms. A trinomial is a sum of three monomialsand has three terms. A general polynomial is a monomial ora sum of monomials and has one or more terms.54. 55. 56. 57.58. 59. 16 ft by 8 ft
1. (a) , 8, , 7, ; (b) 13, 8, 7; both 7 and 12 arepositive; (c) 2.3. The coefficient of the middle term, , is negative.4. 5. 6. (a) 23, 10, 5, 2;the positive factor has the larger absolute value; (b) ,
, , ; the negative factor has the larger absolutevalue; (c) 7. (a) , , , ; thenegative factor has the larger absolute value; (b) 23, 10, 5, 2;the positive factor has the larger absolute value; (c) 8.9. 10.11. 12. Prime 13.14. 15.16. , or , or
1. Length: 24 in.; width: 12 in. 2. Height: 25 ft; width: 10 ft3. (a) 342 games; (b) 9 teams 4. 22 and 23 5. 24 ft6. 3 m, 4 m
Translating for Success, p. 381
1. O 2. M 3. K 4. I 5. G 6. E 7. C 8. A9. H 10. B
Exercise Set 5.9, p. 382
1. Length: 6 cm; width: 4 cm 3. Length: 12 ft; width: 2 ft5. Height: 4 cm; base: 14 cm 7. Base: 8 m; height: 16 m9. 182 games 11. 12 teams 13. 4950 handshakes15. 25 people 17. 20 people 19. 14 and 1521. 12 and 14; and 23. 15 and 17; and �17�15�14�12
25. Hypotenuse: 17 ft; leg: 15 ft 27. 32 ft 29. 9 ft31. Dining room: 12 ft by 12 ft; kitchen: 12 ft by 10 ft33. 4 sec 35. 5 and 7 37. 39. Factor40. Factor 41. Product 42. Common factor43. Trinomial 44. Quotient rule 45. y-intercept46. Slope 47. 35 ft 49. 5 ft 51. 30 cm by 15 cm53. 7 ft
; 16 and 18 42. and ; 17 and 19 43. 3 ft44. 6 km 45. 46.47. Answers may vary. The area of a rectangle is The length is 1 m greater than the width. Find the lengthand the width. 48. Because Sheri did not first factorout the largest common factor, 4, her factorization will notbe “complete” until she removes a common factor of 2 fromeach binomial. 49. 2.5 cm 50. 0, 2 51. Length: 12; width: 6 52. No solution 53. 2, , 54.55.
You get the same number you selected. To do a numbertrick, ask someone to select a number and then performthese operations. The person will probably be surprisedthat the result is the original number.
method 1: used to multiply by 1 using method 2:LCM of the denominators in the numerator used to subtractin the numerator and LCM of the denominators in the denominator used to add in the denominator
� y � �5 � y � 4��x � �3 � x � 3�;range � ��3, �2, 2, 3�Domain � ��3, �2, 0, 2, 5�;
g�x� � 154 x �
134
DW
�2 21 4
2
�2
�4
�4�5 �3 �1�1
�3
�5
345
3 5
y
x
f (x)� x 3 � 1
�2 21 4
�2
�4
�4�5 �3 �1�1
�3
�5
1
345
3 5
y
x
f (x)� 2 � x 2
x
y
f (x) � x 2 � x � 2
x
y
f (x) � x 2
A-30
Answers
5. (a) (b) ; (c) 0; (d)7. (a) 1; (b) all real numbers; (c) 3; (d) all real numbers9. (a) 1; (b) all real numbers; (c) �2, 2; (d)11. (a) �1; (b) ; (c) �4, 0, 3; (d) 13. is a real number and15. All real numbers 17. All real numbers 19. is areal number and 21. All real numbers
23. is a real number and25. is a real number and27. All real numbers 29. All real numbers31. is a real number and 33. All real numbers
35. is a real number and 37. �8; 0; �2
39. 41. 42. 43.
44. 45. R 2; or
46. R or
47.
48. 49. 50.51. is a real number and
Margin Exercises, Section 7.3, pp. 503–510
1. The graph of looks just like the graph of
but it is moved down6 units.
2. The graph of looks just like the graph of
but it is moved up3 units.
3. The graph of looks justlike the graph of but itis moved up 2 units.
4. 5. �0, � 23��0, 8�
f �x�,g�x�
x
y
g(x) � ax � 2
f (x) � ax
y � �2x,
y � �2x � 3
x
y
y � �2x � 3y � �2x
y � 3x,
y � 3x � 6
x
y
y � 3x y � 3x � 6
� y � y � 0�� y � y � �4�;� y � y � 2�;y � 0�;� y � y
11. The rate of change is 3 haircuts per hour.12. �0.141 reports per 1000 passengers per year
Calculator Corner, p. 502
1. The graph of is the same as the graph ofbut it is moved up 4 units. 2. The graph of
is the same as the graph of but it ismoved down 3 units. 3. The graph of will bethe same as the graph of but it will be moved up8 units. 4. The graph of will be the same as thegraph of but it will be moved down 5 units.
Calculator Corner, p. 506
1. The graph of will slant up from left to right. Itwill be steeper than the other graphs. 2. The graph of
will slant up from left to right. It will be less steep than the other graphs. 3. The graph of will slant down from left to right. It will be steeper than the other graphs. 4. The graph of will slant down from left to right. It will be less steep than theother graphs.
19. 21. 23. 25.27. or 8% 29. 3.5% 31. The rate of change is5.06 billion messages daily per year. 33. The rate ofchange is �$900 per year. 35. The rate of change is onepoint per $1000 of family income. 37. 39. �1323
40. 41. 42. 2543. Square: 15 yd; triangle: 20 yd
350x � 60y � 12045x � 54
DW
225 ,
m � � 13m � 2
3m � 2m � 13
m � � 12�0, 4
17�m � 0;�0, 12�m � �8;�0, �2�m � 3;
�0, � 83�m � 2
3 ;�0, �9�m � 0.5;�0, �
15�m � �
38 ;�0, �6�
m � �2;�0, 5�m � 4;
y � �0.005x
y � �10xy � 0.005x
y � 10x
y1 � x,y � x � 5
y1 � x,y � x � 8
y1 � x,y3 � x � 3y1 � x,
y2 � x � 4
�0, � 52�
12 ;�0, 23�
m � � 23m � �
13
x
y
(3, 1)(0, 2)
m � �1
x
y
(�1, �1)
(2, �4)
A-31
Chapter 7
44.45.46.
47. R �4; or
Margin Exercises, Section 7.4, pp. 514–519
1. 2.
3. 4.
5. 6.
7. 8.
x
y
x � �5
x
y
y � 3.6
m � 0
x
y
f (x) � �4
m � 0
x
y
(0, �4)
(�3, 1)
y � �fx � 4
x
y
(0, 5)
(5, 2)
g(x) � �Ex � 5
x
y
(0, �2)
(4, 1)
f (x) � !x � 2
(�4, �5)
x
y
(�2, �2)
(2, 4)
(0, 1)
y � wx � 1
x
y
4y � 12 � �6xy-intercept(0, 3)
x-intercept(2, 0)
a � 10 ��4
a � 1a � 10,
7�2x � 1� �4x2 � 2x � 1��c � d � �c2 � cd � d2� �c � d � �c2 � cd � d2��2 � 5x� �4 � 10x � 25x2�
1. No 2. Yes 3.4. 5. About $6810 6. Yes7. No 8. (a) (b) ; (c) �1; (d) 9. is a real number and10. All real numbers 11. Slope: �3; y-intercept: 12. Slope: y-intercept: 13.14. 15.
16. 17.
18. 19.
20. Perpendicular 21. Parallel 22. Parallel
23. Perpendicular 24.25. 26. 27.28. 29. (a)(b) about 44.37 sec; 44.24 sec 30. The concept ofslope is useful in describing how a line slants. A line withpositive slope slants up from left to right. A line withnegative slope slants down from left to right. The larger theabsolute value of the slope, the steeper the slant.
DWR�x� � �0.064x � 46.8;y � 1
3 x �13
y � � 57 x � 9y � �
32 xy � �3x � 4
f �x� � 4.7x � 23
x
y
f(x) � 4
x
y
x � �3
x
y
f(x) � ex � 3x
y
g(x) � �sx � 4
x
y
(2, 0)
(0, 3)
2y � 6 � 3x
x
y
(4, 0)
(0, 2)
2y � x � 4
m � 113�0, 2��
12 ;
�0, 2�x � 4��x � x� y � 1 � y � 5�
�x � �2 � x � 4�f �2� � 3;f �0� � 7; f ��1� � 12
g�0� � 5; g��1� � 7
4y � 9
x � 32�x � 5�
b � 1DW
M�t� � 0.236 t � 71.8;R�t� � �0.075t � 46.8;
A-34
Answers
31. The notation can be read “f of x” or “f at x” or“the value of f at x.” It represents the output of the functionf for the input x. The notation provides a conciseway to indicate that for the input a, the output of thefunction f is b. 32.
Test: Chapter 7, p. 543
1. [7.1c] 2. [7.1c]
3. [7.1e] (a) 8.666 yr; (b) 1998 4. [7.1a] Yes 5. [7.1a] No6. [7.1b] �4; 2 7. [7.1b] 7; 8 8. [7.1d] Yes9. [7.1d] No 10. [7.1e] (a) About 32 million persons; (b) about 80 million persons 11. [7.2a] (a) 1.2; (b) (c) �3; (d)12. [7.2a] All real numbers 13. [7.2a] is a realnumber and 14. [7.3b] Slope: y-intercept: 15. [7.3b] Slope: y-intercept: 16. [7.3b] 17. [7.3b] 18. [7.3c]
13. No solution; inconsistent; independent 15. Infinitelymany solutions; consistent; dependent 17.consistent; independent 19. consistent;independent 21. Consistent; independent; F23. Consistent; dependent; B 25. Inconsistent;independent; D 27. 29.30. 31. 33.
Margin Exercises, Section 8.2, pp. 558–560
1. 2. 3. 4. 5. (a) Nosolution; (b) the same, no solution 6. Length: 160 ft;width: 100 ft
Calculator Corner, p. 558
Left to the student
Exercise Set 8.2, p. 561
1. 3. 5. 7.
9. 11. 13. 15. No solution17. Length: 40 ft; width: 20 ft 19. 48° and 132°21. Wins: 23; ties: 14 23. 25. 1.3
26. 27. 28. 29.
31. Length: 57.6 in.; width: 20.4 in.
Margin Exercises, Section 8.3, pp. 564–569
1. 2. 3. 4.5. 6. No solution 7. Infinitely manysolutions 8.9. 10. (a) Length: 160 ft; width: 100 ft; (b) the solutions are the same.
Calculator Corner, p. 567
1. We get and Since the graphsare parallel lines, the system of equations has no solution.
2. Each equation is equivalent to or
Since the equations are equivalent, the graphs are the sameand every solution of one is also a solution of the other.Thus we have an infinite number of solutions.
Exercise Set 8.3, p. 570
1. 3. 5. 7.
9. 11. 13. 15. Infinitely
many solutions 17. No solution 19.21. 23. 25.27. Length: 110 m; width: 60 m 29. 14° and 76°31. Coach-class: 131; first-class: 21 33. 35. 136. 5 37. 3 38. 291 39. 15 40.41. 53 42. 8.92 43. is a real number and x � �7��x � x
1. consistent; independent 2. Infinitely manysolutions; consistent; dependent 3. No solution; inconsistent; independent 4. 5. No solution
6. 7. 8. 9.10. Infinitely many solutions 11. CD: $14; cassette: $912. 5 L of each 13. 14.
15. 16. 17.
18. 19. $20 bills: 5; $5 bills: 15; $1 bills: 1920. (a) (b)(c) (d) $115,000 profit; $10,000 loss; (e) 21. 22. The comparison is summarized in the table in Section 8.3. 23. Manyproblems that deal with more than one unknown quantityare easier to translate to a system of equations than to asingle equation. Problems involving complementary orsupplementary angles, the dimensions of a geometricfigure, mixtures, and the measures of the angles of a triangleare examples.
13. , or ���, �5� � ��2, ���x � x � �2 or x �5�0�2
r
���, �2� � �72 , ���x � x
72 or x �2�
0 1 6
���, 1� � �6, ���x � x 1 or x 6�
���, �2� � �4, ��0�2 4
A
B
15. , or
0�1
��1, ���x � x � �1� 17. , or
60
���, 6�� y � y 6�
19. , or
21. , or
0�4
��4, ���t � t �4�0�10
�22
���, �22��a � a � �22�
23. , or
�6 0
��6, ��� y � y � �6� 25. , or
0 4
9
���, 9��x � x � 9�
27. , or
0 3
�3, ���x � x 3�
29. , or
�60 �30 0
���, �60��x � x �60� 31.
30
�x � x � 3�, or �3, ��
33. , or
35. , or 37. , or
39. , or 41. , or 43. , or
45. , or 47. , or
49. , or 51. , or
53. , or 55. , or
57. , or 59. , or
61. , or 63. , or
65. , or 67. , or 69. , or 71. 73.75. 77.79. 81. 83.85. (a) 8.398 gal, 12.063 gal, 15.728 gal; (b) years after 199987. 89. 90.91. 92.93.94. All real numbers 95. All real numbers96.97. (a) ; (b) 99. True101. All real numbers 103. All real numbers
Margin Exercises, Section 9.2, pp. 631–637
1. 2.
3. ;
4. , or ;
5. ;
0�3
�x � x �3�
�5 10
0 4
��5, 10��x � �5 x � 10�
��1, 4��1 40
A
B
�0, 3�
� p � p 10�� p � p � 10��x � x is a real number and x � 2
3�
�x � x is a real number and x � �8�t 2 � 7st � 18s26a2 � 7a � 55
6r 2 � 23rs � 4s23x2 � 20x � 32DW
�s � s � 8�� p � p � 80��n � n � 25��S � S � $7000��B � B $11,500�
�S � S 84��W � W �approximately� 189.1 lb����, 2��a � a � 2�
65. Left to the student 67. Left to the student69. Left to the student
Concept Reinforcement, p. 669
1. False 2. True 3. True 4. True 5. False
Summary and Review: Chapter 9, p. 670
1. 2.3. ;
4. ;
5. , or 6. , or 7. , or 8. , or 9. , or
10. , or 11. , or
12. , or
13. , or 14.15. $10,000 16. 17.18. ;
19. ; 20.
21. , or ��7, 2��x � �7 � x � 2�
����, �2� � �5, ��0�2 5
��2, 5��2 50
�1, 2, 3, 5, 6, 9��1, 5, 9��t � t � 4
14 hr����, �
52��x � x � �
52�
��10, ��� y � y � �10����, �3��x � x � �3����, �
65�� y � y � �
65�
��3, ���x � x � �3���30, ��� y � y � �30���4, ��� y � y � �4���7, ��� y � y � �7�
���, �21��a � a � �21�
�1, ��0 1
���, �2�0�2
���, 40���8, 9�
20
40
�20
�40
�20 20�40
w
hw � h � 502w � 2h � 30 � 130,w � h � 32,w � h � 30 � 62,h � 0,w � 0,
2�1 � a��2 � 2a�,y � 6
y � � 32
x �52y � 9
2 x � 9y � �3x � 15
y � 38
xy � 12
x �72
DW
x
y
(5, 0)(0, 0)
(0, 4)
6
8
(Ç, Ç)40 2411 11
x
y
(0, 6) (4, 4)
(6, 0)(0, 0)
8
8
x
y
(w, �q)
x
y
(0, 1)
(2, �3)
(2, 5)
A-41
Chapter 9
22. , or 23. , or 24. , or
25. , or 26.
27. 28. 29. 62 30. 6, �6 31.
32. 33. 34. , or
35. , or
36. , or 37.38. , or approximately between 1991 and 1996
39. 40.
41. 42.
43. 44.
45. (1) , not . (2) Thiswould be correct if (1) were correct except that theinequality symbol should not have been reversed. (3) If (2) were correct, the right-hand side would be �5, not8. (4) The inequality symbol should be reversed. Thecorrect solution is
.
46. “Solve” can mean to find all the replacements thatmake an equation or inequality true. It can also mean toexpress a formula as an equivalent equation with a givenvariable alone on one side.47. , or ��
1. [7.5e] (a) (b) 3.50 min; 3.49 min2. [7.3c] 4% per year 3. [1.8b] 47b � 51
R�x� � �0.006x � 3.85;
�x � 15 � x �
45�, or �1
5 ,
45��
(�2, 0)
(��, ��)9 4
1 2
�2 21 4
�2�1
�4
�4�5 �3 �1
�3
�5
1
32
45
5
y
x
(4, �1)
x
y
x
y
x � 6y , �6
�x � x � � 135 or x �
75�, or ���, �
135 � � �
75
, ���x � �99 � x � 111�, or ��99, 111��x � x � �3 or x � 3�, or ���, �3� � �3, ��
�x �� 78 � x �
118 �, or ��
78
,
118 ��
�1���6, 12���9, 9��1, 3, 5, 7, 9, 11, 13��3, 5�
2�x�7�x�
���, 3� � �6, ���x � x � 3 or x � 6����, ��
���, �4� � �� 52 , ���x � x � �4 or x � �
52�
�� 25 , 9
5��x �� 25 � x �
95�
��1, 6��x � �1 � x � 6��4, ���x � x � 4�
���, �3� � �4, ��0�3 4
��3, 4��3 40
�d � 33 ft � d � 231 ft��h � h � 2
110 hr����, 7
4��x � x �74�
�52 , ���x � x �
52�
�1, ��� y � y � 1����, 11
5 ��a � a �115 �
��50, ��� y � y � �50��x � x � 10�, or �10, ��
���, �2�0�2
���, 6�60
��4, ����3, 2�
A-42
Answers
4. [1.8d] 224 5. [4.2a, b] 6. [4.4c]
7. [4.6c]
8. [4.6a] 9. [6.1d]
10. [6.2b] 11. [6.5a]
12. [6.5b] 13. [6.6a]
14. [6.6a] 15. [4.8b]
16. [2.3c] 17. [2.4b]
18. [9.2a] or
19. [9.1c] or
20. [9.3e] or 21. [9.3c] 22. [9.3e] or or 23. [8.2a], [8.3a] Infinite number of solutions24. [8.5a] 25. [5.8b] 26. [5.8b] 27. [6.7a] No solution 28. [6.7a]
1. 2. 3. 4. 1 5. 6 6.7. 0.08 8. (a) 4; (b) (c) does not exist as a realnumber 9. (a) 7; (b) (c) does not exist as a realnumber 10. (a) 12; (b) (c) does not exist as a real number 11. 12. 13. 1.2 14. 4.12315. 6.325 16. 33.734 17. 18. 0.793
19. 20. 21. 22. 2;
does not exist as a real number23. does not exist as a real number24. Domain
25. Domain
26. 27.
28. 29. 24 30. 31. 32.33. 34. 35. 36.37. 38. 39.40. 41. 3 42.43. 44. 45. 0 46. 47. 48. 349. 50. Does not exist as a real number 51. 052. 53. 54. 55. 56.
52. 9 cm 53. 4.899 ft 54. About 4166 rpm55. 4480 rpm 56. 25 57. 6.78258. 59. 60. 61. 2962. 63. 64. 65. 3 66. No67.
68. The procedure for solving radical equations is toisolate one of the radical terms, use the principle of powers,repeat these steps if necessary until all radicals areeliminated, solve, and then check the possible solutions. A check is necessary since the principle of powers does notalways yield equivalent equations. 69. 70. 3
Test: Chapter 10, p. 751
1. [10.1a] 12.166 2. [10.1a] 2; does not exist as a realnumber 3. [10.1a] Domain or 4. [10.1b] 5. [10.1b] 6. [10.1c] 7. [10.1d] 8. [10.1d] 4 9. [10.2a] 10. [10.2a] 8 11. [10.2a] 12. [10.2a]
1. Two real 2. One real 3. Two nonreal4. 5.6. 7. 8.9. 4 10. 11.
Exercise Set 11.4, p. 793
1. One real 3. Two nonreal 5. Two real 7. One real9. Two nonreal 11. Two real 13. Two real 15. Onereal 17. 19.21. 23.25.27. 29. 31. 1, 8133. 35. 37. 1 39. 1, 4, 6
1. 180 ft by 180 ft 3. 3.5 in. 5. 3.5 hundred, or 3507. 10 ft by 20 ft 9. 11 days after the concert wasannounced; about 62 11.$237,100 at 13. 121; 11 and 11 15. 2 and
17. 36; and 19.21. 23. Polynomial, neitherquadratic nor linear 25.27. 29.31. (a) (b) about 531 per200,000,000 kilometers driven33.35. 37. Radical; radicand 38. Dependent39. Sum 40. At least one 41. Inverse42. Independent 43. Descending 44. x-intercept45. ,where x is the number of years after 1997
Margin Exercises, Section 11.8, pp. 832–837
1. or 2. or 3. or
4. or 5. or 6.or 7. or 8. or ���, 5� � �10, ���x � x � 5 or x � 10�,
�2, 72��x � 2 � x �
72�,���, �1� � �0, 1�
�x � x � �1 or 0 � x � 1�,��4, 1��x � �4 � x � 1�,���, �4� � �1, ���x � x � �4 or x � 1�,��3, 1�
�x � �3 � x � 1�,��3, 1��x � �3 � x � 1�,���, �3� � �1, ���x � x � �3 or x � 1�,
point lies halfway between the x-coordinates of the x-intercepts. The function must be evaluated for this valueof x in order to determine the maximum or minimum value.37. minimum: 38. 39. 18 and 324
Test: Chapter 11, p. 843
1. [11.1a] (a) (b)
2. [11.2a] 3. [11.4c] 49, 1 4. [11.2a] 9, 2
5. [11.4c]
6. [11.2a] 0.449, 7. [11.2a] 0, 2
8. [11.1b] 9. [11.1c] About 6.7 sec10. [11.3a] About 2.89 mph 11. [11.3a] 7 cm by 7 cm12. [11.1c] About 0.866 sec 13. [11.4a] Two nonreal14. [11.4b]
15. [11.3b] or 16. [11.6a] (a)
(b) (c) maximum: 1; (d)
17. [11.6a] (a) (b) (c) minimum: 5; (d)
18. [11.6b] y-intercept: x-intercepts: 19. [11.7a] 4 and 20. [11.7b] 21. [11.7b] (a) (b) about$2617 billion; about $3085 billion22. [11.8a] or 23. [11.8b] or 24. [11.8b] or 25. [11.6a, b], [11.7b] ; maximum:
26. [11.2a] 27. [11.4c] �2, �2, �2i, �2i12
817f �x� � �
47 x2 �
207 x � 8
��3, 1� � �2, ���x � �3 � x � 1 or x 2�,��3, 5��x � �3 � x � 5�,��1, 7��x � �1 � x � 7�,
1. is the power to which we raise 2 to get 64; 62. 3.
4.5.6.
7. 8. 9. 10.11. 10,000 12. 3 13. 14. 4 15. 16. 017. 0 18. 1 19. 1 20. 0 21. 4.893422. 23. Does not exist as a real number24. between 3 and 4; 3.994525.
26. 78,234.8042
Exercise Set 12.3, p. 885
1.
3. 5.
7. 9. 11.
13. 15. 17.19. 21. 23.25. 27. 29.31. 33. 35. 9 37. 4 39. 441. 3 43. 25 45. 1 47. 49. 2 51. 253. 55. 0 57. 4 59. 2 61. 3 63.65. 0 67. 1 69. 71. 4.8970 73.75. Does not exist as a real number 77. 0.946479.
81.83. Conjugate 84. Direct 85. Coefficient; exponent
1. About 65 decibels 2. 3. About 4.94. moles per liter 5. (a) 43.5 yr; (b) 16.5 yr6. About 300 million; about 344 million 7. (a)
(b) $5309.18; $5637.48; $9110.59; (c) about11.6 yr 8. (a) where is inbillions of dollars and is the number of years after 2000; (b) about $34,531 billion, or $34.531 trillion; (c) 20089. 2972 yr
Calculator Corner, pp. 918–919
1.2. 3. 3,531,046 businesses
y � 309,870.3567 � 1.090787419x
tP�t�P�t� � 2.8e0.471t,k � 0.471,
P�t� � 5000e0.06t;k � 6%,
10�710�9.2 W�m2
�710100,000�34
�4�1.5318�1.9617;
�iy4/3
25x2z4
�1
10 , 1�2, �3, �5 � 41
2�64, 8
�10, �2DW25
13
1e
� 0.3679
e2 � 7.38911100
132
32�3, �15
2
35
52
25
�52 , �����, 100����, ��;
�0, �����, ��;�3, �4
14 , 9DW
x
y
f (x) � u ln x u
x
y
f (x) � q ln x � 1
A-59
Chapter 12
Translating for Success, p. 920
1. D 2. M 3. I 4. A 5. E 6. H 7. C 8. G9. N 10. B
Exercise Set 12.7, p. 921
1. About 95 dB 3. or about5. About 6.8 7. moles
per liter 9. 11.13. (a) 243 people; (b) about 20.6 months; (c) about 0.6 month 15. (a) $19,796; (b) 2011; (c) 11.9 yr17. (a) (b) 6.9 billion; (c) 2043; (d) 60.8 yr19. (a) (b) $5309.18; $5637.48; $9110.59; (c) in 11.6 yr 21. (a)(b) 2,888,380; (c) 2027 23. About 2103 yr 25. About7.2 days 27. 69.3% per year 29. (a)
(b) 4.7 million tons; (c) 217331. (a) (b) $2,419,866; (c) 9.9 yr; (d) 2002; (e) The function predicts that the card’s value willbe about $908,202 in 2001. According to this, the card wouldnot be a good buy at $1.1 million. 33. (a)
(b) about 2,081,949; (c) 211535. 37. 38. 1 39. i 40. i 41.42. 43. 44. 45. 4146. 47. 1.078, 58.77049. 2, 4 51. $13.4 million
55. (a) (b) $102,399; (c) after 8 yr, or in 2013 56.57. About 8.25 yr 58. About 3463 yr 59. Youcannot take the logarithm of a negative number becauselogarithm bases are positive and there is no real-numberpower to which a positive number can be raised to yield anegative number. 60. because
61. 62.
Test: Chapter 12, p. 930
1. [12.1a] 2. [12.3a]
3. [12.5c] 4. [12.5c]
5. [12.2a]
6. [12.2b, c]
7. [12.2b, c] 8. [12.2b] Not one-to-one9. [12.2d] 10. [12.3b] 11. [12.3b] 12. [12.3c] 3 13. [12.3c] 23 14. [12.3c] 015. [12.3d] 16. [12.3d] Does not exist as a realnumber 17. [12.4d]
30. [12.6b] 9 31. [12.6b] 1 32. [12.7a] 4.233. [12.7b] (a) $31,081; (b) 2010; (c) 15.7 yr34. [12.7b] (a) where t is thenumber of years since 2000 and N is in millions; (b) 33.672 million, 35.862 million; (c) 2052; (d) 77.0 yr35. [12.7b] About 4.6% 36. [12.7b] About 4684 yr37. [12.6b] 44, 38. [12.4d] 2
Cumulative Review/Final Examination, p. 933
1. [1.2e] 2. [4.1e, f ] 3. [1.8d] 62.54. [1.8c] 5. [9.1c] or 6. [9.3e] or 7. [9.2a] or 8. [8.2a], [8.3a] 9. [8.5a]
10. [5.8b] 11. [6.7a] 12. [10.6a] 4
13. [5.8b] 14. [11.2a]
15. [11.4c] 16. [6.7a] 17. [12.6b] 1 18. [12.6a] 1.748 19. [12.6b] 920. [11.8a] or 21. [11.8b] or
22. [2.4b]
23. [12.1c], [12.7b] (a) About 74.97 billion about84.94 billion (b) about 39 yr; (c)
57. [7.2a] 58. [7.2a] All real numbers 59. [9.1d] More than 460. [6.8a] 612 mi 61. [2.6a] 62. [8.4a] 24 L of A; 56 L of B 63. [6.8a] 350 mph64. [6.8a] 65. [6.9f] 20 66. [11.7a] 67. [12.7b] 2397 yr 68. [6.9d] 3360 kg69. [7.5c] f �x� � �
AAbscissa The first coordinate in an ordered pair of
numbersAbsolute value The distance that a number is from 0 on
the number lineac-method A method for factoring trinomials of the type
involving the product, ac, of theleading coefficient a and the last term c
Additive identity The number 0Additive inverse A number’s opposite; two numbers are
additive inverses of each other if their sum is 0Algebraic expression An expression consisting of
variables, constants, numerals, and operation signsArea The number of square units that fill a plane regionArithmetic numbers The whole numbers and the positive
fractionsAscending order When a polynomial is written with the
terms arranged according to degree from least to greatest, it is said to be in ascending order.
Associative law of addition The statement that whenthree numbers are added, regrouping the addends givesthe same sum
Associative law of multiplication The statement thatwhen three numbers are multiplied, regrouping the factors gives the same product
Asymptote A line that a graph approaches more and moreclosely as x increases or as x decreases
Average A center point of a set of numbers found byadding the numbers and dividing by the number ofitems of data; also called the arithmetic mean or mean
Axes Two perpendicular number lines used to identifypoints in a plane
Axis of symmetry A line that can be drawn through agraph such that the part of the graph on one side of the line is an exact reflection of the part on the opposite side
BBar graph A graphic display of data using bars
proportional in length to the numbers representedBase In exponential notation, the number being raised to
a power
Binomial A polynomial composed of two termsBreak-even point In business, the point of intersection of
the revenue function and the cost function
CCircle A set of points in a plane that are a fixed distance r,
called the radius, from a fixed point called thecenter
Circumference The distance around a circleCoefficient The numerical multiplier of a variableCommon logarithm A logarithm with base 10Commutative law of addition The statement that when
two numbers are added, changing the order in whichthe numbers are added does not affect the sum
Commutative law of multiplication The statement thatwhen two numbers are multiplied, changing the orderin which the numbers are multiplied does not affect theproduct
Completing the square Adding a particular constant to an expression so that the resulting sum is a perfectsquare
Complex fraction expression A rational expression thathas one or more rational expressions within its numerator and/or denominator
Complex number Any number that can be written aswhere a and b are real numbers
Complex rational expression A rational expression thathas one or more rational expressions within its numerator and/or denominator
Complex-number system A number system that containsthe real-number system and is designed so that negative numbers have square roots
Composite function A function in which a quantity depends on a variable that, in turn, depends on another variable
Composite number A natural number, other than 1, thatis not prime
Compound inequality A statement in which two or moreinequalities are combined using the word and or theword or
Compound interest Interest computed on the sum of anoriginal principal and the interest previously accruedby that principal
Conic section A curve formed by the intersection of aplane and a cone
Conjugates Pairs of radical terms, like and or and for which the
product does not have a radical termConjunction A sentence in which two statements are
joined by the word andConsecutive even integers Even integers that are two
units apartConsecutive integers Integers that are one unit apartConsecutive odd integers Odd integers that are two units
apartConsistent system of equations A system of equations
that has at least one solutionConstant A known numberConstant function A function given by an equation of the
form where b is a real numberConstant of proportionality The constant in an equation
of direct or inverse variationCoordinates The numbers in an ordered pairCube root The number c is called a cube root of a if
DDegree of a polynomial The degree of the term of highest
degree in a polynomialDegree of a term The sum of the exponents of the
variablesDemand function A function modeling the relationship
between the price of a good and the quantity of thatgood demanded
Denominator The number below the fraction bar in afraction
Dependent equations The equations in a system are dependent if one equation can be removed withoutchanging the solution set.
Descending order When a polynomial is written with theterms arranged according to degree from greatest toleast, it is said to be in descending order.
Determinant The determinant of a two-by-two matrix
is denoted and represents
Diameter A segment that passes through the center of acircle and has its endpoints on the circle
Difference of cubes Any expression that can be written inthe form
Difference of squares Any expression that can be writtenin the form
Direct variation A situation that translates to an equationof the form with k a positive constant
Discriminant The radicand, from the quadraticformula
Disjoint sets Two sets with an empty intersectionDisjunction A sentence in which two statements are
joined by the word orDistributive law of multiplication over addition The
statement that multiplying a factor by the sum of twonumbers gives the same result as multiplying the factorby each of the two numbers and then adding
Distributive law of multiplication over subtraction Thestatement that multiplying a factor by the difference oftwo numbers gives the same result as multiplying thefactor by each of the two numbers and then subtracting
Domain The set of all first coordinates of the ordered pairsin a function
Doubling time The time necessary for a population todouble in size
EElimination method An algebraic method that uses the
addition principle to solve a system of equationsEllipse The set of all points in a plane for which the sum
of the distances from two fixed points and is constant
Empty set The set without membersEquation A number sentence that says that the
expressions on either side of the equals sign, �, represent the same number
Equation of direct variation An equation, described bywith k a positive constant, used to represent
direct variationEquation of inverse variation An equation, described by
with k a positive constant, used to represent inverse variation
Equilibrium point The point of intersection between thedemand function and the supply function
Equivalent equations Equations with the same solutionset
Equivalent expressions Expressions that have the samevalue for all allowable replacements
Equivalent inequalities Inequalities that have the samesolution set
Evaluate To substitute a value for each occurrence of avariable in an expression
Exponent In expressions of the form the number n isan exponent. For n a natural number, represents nfactors of a.
Exponential decay A decrease in quantity over time thatcan be modeled by an exponential equation of the form
Exponential equation An equation in which a variable appears as an exponent
Exponential function A function that can be described byan exponential equation
Exponential growth An increase in quantity over time thatcan be modeled by an exponential function of the form
Exponential notation A representation of a number usinga base raised to a power
FFactor Verb: To write an equivalent expression that is a
product. Noun: A multiplierFactorization of a polynomial An expression that names
the polynomial as a productFixed costs In business, costs that are incurred whether or
Focus One of two fixed points that determine the points ofan ellipse
FOIL To multiply two binomials by multiplying the Firstterms, the Outside terms, the Inside terms, and thenthe Last terms
Formula An equation that uses numbers or letters to rep-resent a relationship between two or more quantities
Fraction equation An equation containing one or morerational expressions; also called a rational equation
Fraction expression A quotient, or ratio, of polynomials;also called a rational expression
Fraction notation A number written using a numeratorand a denominator
Function A correspondence that assigns to each memberof a set called the domain exactly one member of a setcalled the range
GGrade The measure of a road’s steepnessGraph A picture or diagram of the data in a table; a line,
curve, or collection of points that represents all the solutions of an equation
Greatest common factor (GCF) The common factor of apolynomial with the largest possible coefficient and thelargest possible exponent(s)
HHalf-life The amount of time necessary for half of a
quantity to decayHypotenuse In a right triangle, the side opposite the right
angle
IIdentity Property of 1 The statement that the product of a
number and 1 is always the original numberIdentity Property of 0 The statement that the sum of a
number and 0 is always the original numberImaginary number A number that can be named bi,
where b is some real number and Imaginary number i The square root of �1; that is,
and Inconsistent system of equations A system of equations
for which there is no solutionIndependent equations Equations that are not dependentIndex In the radical the number n is called the index.Inequality A mathematical sentence using �, �, �, �, or Input A member of the domain of a functionIntegers The whole numbers and their oppositesIntercept The point at which a graph intersects the x- or
y-axisIntersection of two sets The set of all elements that are
common to both setsInterval notation The use of a pair of numbers inside
parentheses and brackets to represent the set of allnumbers between those two numbers
Inverse relation The relation formed by interchanging themembers of the domain and the range of a relation
Inverse variation A situation that translates to an equa-tion of the form with k a positive constant
Irrational number A real number that cannot be namedas a ratio of two integers
JJoint variation A situation that translates to an equation
of the form with k a constant
LLeading coefficient The coefficient of the term of highest
degree in a polynomialLeading term The term of highest degree in a polynomialLeast common denominator (LCD) The least common
multiple of the denominatorsLegs In a right triangle, the two sides that form the right
angleLike terms Terms that have exactly the same variable
factorsLine of symmetry A line that can be drawn through a
graph such that the part of the graph on one side of theline is an exact reflection of the part on the oppositeside
Linear equation Any equation that can be written in theform or where x and y are variables
Linear function A function that can be described by anequation of the form where x and y are variables
Linear inequality An inequality whose related equation isa linear equation
Linear programming A branch of mathematics involvinggraphs of inequalities and their constraints
Logarithmic equation An equation containing a logarith-mic expression
Logarithmic function, base a The inverse of an exponen-tial function with base a
MMaximum value The largest function value (output)
achieved by a functionMean A center point of a set of numbers found by adding
the numbers and dividing by the number of items ofdata; also called the arithmetic mean or average
Median In a set of data listed in order from smallest tolargest, the middle number if there is an odd number ofdata items, or the average of the two middle numbers ifthere is an even number of data items
Minimum value The smallest function value (output)achieved by a function
Mode The number or numbers that occur most often in aset of data
Monomial A constant, a variable, or a product of a constant and one or more variables
Motion problem A problem that deals with distance,speed, and time
Multiple of a number A product of the number and somenatural number
Multiplication property of 0 The statement that the product of 0 and any real number is 0
Multiplicative identity The number 1Multiplicative inverses Reciprocals; two numbers whose
product is 1
NNatural logarithm A logarithm with base eNatural numbers The counting numbers: 1, 2, 3, 4, 5, …Nonlinear function A function whose graph is not a
straight lineNumerator The number above the fraction bar in a
fraction
OOne-to-one function A function for which different inputs
have different outputsOpposite The opposite, or additive inverse, of a number a
is written �a. Opposites are the same distance from 0on the number line but on different sides of 0.
Opposite of a polynomial To find the opposite of a polynomial, replace each term with its opposite—that is, change the sign of every term.
Ordered pair A pair of numbers of the form forwhich the order in which the numbers are listed is important
Ordinate The second coordinate in an ordered pair ofnumbers
Origin The point on a graph where the two axes intersectOutput A member of the range of a function
PParabola A graph of a quadratic equationParallel lines Lines in the same plane that never intersect;
two lines are parallel if they have the same slope.Parallelogram A four-sided polygon with two pairs of
parallel sidesPercent notation A representation of a number as parts
per 100Perfect square A rational number p for which there exists
a number a for which Perfect-square trinomial A trinomial that is the square of
a binomialPerimeter The sum of the lengths of the sides of a polygonPerpendicular lines Lines that form a right anglePi (�) The number that results when the circumference of
a circle is divided by its diameter; or 22�7Point–slope equation An equation of the type
where x and y are variablesPolygon A closed geometric figure with three or more
sidesPolynomial A monomial or sum of monomialsPolynomial equation An equation in which two
polynomials are set equal to each other
Polynomial inequality An inequality that is equivalent toan inequality with a polynomial as one side and 0 asthe other
Prime factorization A factorization of a composite num-ber as a product of prime numbers
Prime number A natural number that has exactly two different factors: itself and 1
Prime polynomial A polynomial that cannot be factoredusing only integer coefficients
Principal square root The nonnegative square root of anumber
Principle of zero products The statement that an equation is true if and only if is true or
is true, or both are trueProportion An equation stating that two ratios are equalProportional numbers Two pairs of numbers having the
same ratioPythagorean theorem In any right triangle, if a and b
are the lengths of the legs and c is the length of the hypotenuse, then
QQuadrants The four regions into which the axes divide a
planeQuadratic equation An equation of the form
where Quadratic formula The solutions of
are given by the equation
Quadratic function A second-degree polynomial functionin one variable
Quadratic inequality A second-degree polynomial inequality in one variable
RRadical equation An equation in which a variable appears
in a radicandRadical expression An algebraic expression in which a
radical symbol appearsRadical symbol The symbol Radicand The expression under the radical symbolRadius A segment with one endpoint on the center of a
circle and the other endpoint on the circleRange The set of all second coordinates of the ordered
pairs in a functionRatio The quotient of two quantitiesRational equation An equation containing one or more
rational expressionsRational expression A quotient of two polynomialsRational inequality An inequality containing a rational
expressionRational number A number that can be written in the
form a�b, where a and b are integers and Rationalizing the denominator A procedure for finding
an equivalent expression without a radical in the denominator
Reciprocal A multiplicative inverse; two numbers are reciprocals if their product is 1.
Rectangle A four-sided polygon with four right anglesReflection The mirror image of a graphRelation A correspondence between a first set, the
domain, and a second set, the range, such that eachmember of the domain corresponds to at least onemember of the range
Repeating decimal A decimal in which a number patternrepeats indefinitely
Right triangle A triangle that includes a right angleRise The change in the second coordinate between two
points on a lineRoster notation A way of naming sets by listing all the
elements in the setRounding Approximating the value of a number; used
when estimatingRun The change in the first coordinate between two
points on a line
SScientific notation A representation of a number of the
form where n is an integer, andM is expressed in decimal notation
Set A collection of objectsSet-builder notation The naming of a set by describing
basic characteristics of the elements in the setSimilar triangles Triangles in which corresponding sides
are proportionalSimplify To rewrite an expression in an equivalent,
abbreviated, formSlope The ratio of the rise to the run for any two points on
a lineSlope–intercept equation An equation of the form
where x and y are variablesSolution A replacement or substitution that makes an
equation or inequality trueSolution set The set of all solutions of an equation, an
inequality, or a system of equations or inequalitiesSolve To find all solutions of an equation, an inequality,
or a system of equations or inequalities; to find the solution(s) of a problem
Speed The ratio of distance traveled to the time requiredto travel that distance
Square A four-sided polygon with four right angles and allsides of equal length
Square of a number A number multiplied by itselfSquare root The number c is a square root of a if Substitute To replace a variable with a numberSubstitution method An algebraic method for solving
systems of equationsSum of cubes An expression that can be written in the
form
Sum of squares An expression that can be written in theform
Supply function A function modeling the relationship be-tween the price of a good and the quantity of that goodsupplied
System of equations A set of two or more equations thatare to be solved simultaneously
TTerm A number, a variable, or a product or a quotient of
numbers and/or variablesTerminating decimal A decimal that can be written using
a finite number of decimal placesTotal cost The amount spent to produce a productTotal profit The amount taken in less the amount spent,
or total revenue minus total costTotal revenue The amount taken in from the sale of a
productTrinomial A polynomial that is composed of three termsTrinomial square The square of a binomial expressed as
three terms
UUnion of sets A and B The set of all elements belonging to
either A or B
VValue The numerical result after a number has been
substituted into an expressionVariable A letter that represents an unknown numberVariable expression An expression containing a variableVariation constant The constant in an equation of direct
or inverse variationVertex The point at which the graph of a quadratic
equation crosses its axis of symmetryVertical-line test The statement that a graph represents a
function if it is impossible to draw a vertical line thatintersects the graph more than once
WWhole numbers The natural numbers and 0: 0, 1, 2, 3, …
Xx-intercept The point at which a graph crosses the x-axis
Yy-intercept The point at which a graph crosses the y-axis
of a function, 482, 483, 497, 680of a relation, 483
Doubling time, 913Draw feature on a graphing calculator,
868
Ee, 895, 926Earned run average, 471Elements of a matrix, 984Elimination method, 563, 567Empty set, 633Endpoints of an interval, 615Entries of a matrix, 984Equation, 82. See also Formulas.
with absolute value, 643, 645addition principle, 83, 160algebraic, 2of a circle, 994of direct variation, 462, 463equivalent, 83exponential, 880, 904false, 82fraction, 436 entering on a graphing calculator, 101graphs, 169. See also Graphs.with infinitely many solutions, 99of inverse variation, 464linear, 173, 587logarithmic, 880, 906multiplication principle, 88, 160with no solution, 100containing parentheses, 98point–slope, 526, 527, 540polynomial, 246quadratic, 366quadratic in form, 790radical, 717rational, 436reducible to quadratic, 790related, 655reversing, 90
for one, 946evaluating, 3, 4, 954exponential, 954factoring, 59. See also Factoring.fraction, see Rational expressions radical, 679rational, see Rational expressionssimplifying, see Simplifyingterms, 58value of, 3
HHalf-life, 917Half-plane, 653Handshakes, number possible, 383Hang time, 762Height of a projectile, 839Home-run differential, 36Hooke’s law, 469Horizon, sighting to, 726Horizontal line, 188, 189, 210, 516,
517, 540slope, 204, 210
Horizontal-line test, 863Hypotenuse, 378
Ii, 736, 748
powers of, 739Identity
additive, 53, 945multiplicative, 53, 945
Identity property of one, 53, 76, 945Identity property of zero, 53, 76, 945Imaginary numbers, 736, 748Improper symbol for fractions, 949Inconsistent system of equations, 551,
552, 566, 982Independent equations, 552, 566Index of a radical expression, 683Inequalities, 15, 139, 614
with absolute value, 646addition principle for, 141, 160, 617,
LCD, see Least common denominatorLCM, see Least common multipleLeading coefficient, 317Least common denominator, (LCD),
370, 414, 949
Least common multiple, (LCM), 410,942, 943
of an algebraic expression, 411and clearing fractions, 436
Legs of a right triangle, 378Less than (�), 15Less than or equal to (�), 17Library of functions, 821Like radicals, 706Like terms, 61, 249, 287Line. See also Lines.
Logarithms, 878, 926. See alsoLogarithmic functions.
base a of a, 883, 926base a of 1, 882, 926base e, 895base 10, 883of the base to a power, 892, 926on a calculator, 883change-of-base formula, 896common, 883difference of, 890, 926and exponents, 879
and changing the sign, 26, 66, 260and multiplying by �1, 66of an opposite, 25of polynomials, 260in rational expressions, 398and subtraction, 31, 260of a sum, 66 sum of, 26
Radical function, 680Radical symbol, 679Radicals, see Radical expressionsRadicand, 679Radius, 994Raising a power to a power, 232, 239Raising a product to a power, 233, 239Raising a quotient to a power, 234,
239Range
of a function, 482, 483, 497of a relation, 483
Rate, 450of change, 201, 509. See also Slope.exponential decay, 917exponential growth, 914
Ratio, 450Rational equations, 436Rational exponents, 690, 691Rational expressions, 394. See also
Several variables, polynomial in, 286Sighting to the horizon, 726Sign changes in fraction notation, 48Sign of a reciprocal, 46Signs of numbers, 26Similar triangles, 452, 453Simple interest, 131Simplest fraction notation, 946Simplifying