Intermediate Algebra (11th edition)

3.5–3.6 Determine whether each equation or inequality defines y as a function of x.

Give the domain in each case. Identify any linear functions.

46. 
    
    
    
    47. 
        
        
        
        48. 
            
        
        
        
        
    
    
    
    


47. 
    
    
    
    50. 
        
        
        
        51. 
            
        
        
        
        
    
    
    
    

3.6 Given , find each function value or expression.

52. 53. 54. 55.

56.The equation defines yas a function fof x. Write it using function notation,

and find.

57.Concept Check Suppose that defines yas a function fof x. If ,

which one of the following defines the same function?

A. B.

C. D.

58.The table shows life expectancy at birth in the United States

for selected years.

(a)Does the table define a function?

(b)What are the domain and range?

(c) Call this function ƒ. Give two ordered pairs that belong

to ƒ.

(d)Find What does this mean?

(e) If , what does ƒ 1 x 2 =76.8 xequal?

ƒ 119802.

ƒ 1 x 2 =

2

5

x+

7

5

ƒ 1 x 2 =

2

5

x-

7

5

ƒ 1 x 2 =-

2

5

x-

7

5

ƒ 1 x 2 =-

2

5

x+

7

5

2 x- 5 y= 7 y=ƒ 1 x 2

ƒ 132

2 x^2 - y= 0

ƒa- ƒ 1 k 2

1

2

ƒ 102 ƒ 1 2.1 2 b

ƒ 1 x 2 =- 2 x^2 + 3 x- 6

y=

7

x- 6

y= 24 x+ 7 x=y^2

y= 3 x- 3 y 6 x+ 2 y=|x|

204 CHAPTER 3 Graphs, Linear Equations, and Functions

EXERCISES 59 –70

FOR INDIVIDUAL OR GROUP WORK

Refer to the straight-line graph and work Exercises 59 –70 in order.

59.By just looking at the graph, how can you tell whether

the slope is positive, negative, 0, or undefined?

60.Use the slope formula to find the slope of the line.

61.What is the slope of any line parallel to the line

shown? Perpendicular to the line shown?

62.Find the x-intercept of the graph.

63.Find the y-intercept of the graph.

64.Use function notation to write the equation of the

line. Use ƒ to designate the function.

65.Find.

66.If , what is the value of x?

67.Graph the solution set of.

68.What is the solution set of?

69.What is the solution set of? (Use the graph and the result of Exercise 68.)

70.What is the solution set of ƒ 1 x 270? (Use the graph and the result of Exercise 68.)

ƒ 1 x 260

ƒ 1 x 2 = 0

ƒ 1 x 2 Ú 0

ƒ 1 x 2 =- 8

ƒ 182

RELATING CONCEPTS

Life Expectancy

Year at Birth (years)

1960 69.7

1970 70.8

1980 73.7

1990 75.4

2000 76.8

2009 78.1

Source:National Center for

Health Statistics.

x

y

(^0) (3, –1)
(–1, 5) 2 y = –3x + 7