Intermediate Algebra (11th edition)

SECTION 3.5 Introduction to Relations and Functions 189

Decide whether each relation defines y as a function of x. (Solve for y first if necessary.) Give
the domain. See Example 5.

48. 49. 50.

51. 52. 53.

54. 55. 56.

Solve each problem.

57.The table shows the percentage of students at 4-year public
colleges who graduated within 5 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.

58.The table shows the percentage of full-time college fresh-
men who said they had discussed politics in election years.
(a)Does the table define a function?
(b)What are the domain and range?
(c)Call this function g.Give two ordered pairs that belong
to g.

y= xy= 1 xy= 3

7

x- 2

y=

2

x- 4

y=-

6

x

y=-

2

x

y=

x- 3

2

y=

x+ 4

5

y= 22 x+ 9

y= 2 x- 3 y= 2 x- 7 y= 24 x+ 2

x-y 63 y= 2 x y=- 2 x

x=y^6 x=y^4 x+y 64

y= 6 x+ 8 y=x^2 y=x^3

y=- 6 x y=- 9 x y= 2 x- 6

Source:Cooperative

Institutional Research

Program.

Source:ACT.

Year Percentage

2004 42.3

2005 42.3

2006 42.8

2007 43.7

2008 43.8

Year Percentage

[ 1992 83.7

1996 73.0

2000 69.6

2004 77.4

2008 85.9

Evaluate y for See Section 3.1.

Solve for y. See Section 2.2.

3

4

3 x- 7 y= 8 2 x- 4 y= 7 x+ 2 y= 9

y=- 7 x+ 12 y=- 5 x- 4 y= 3 x- 8

x=3.

PREVIEW EXERCISES