Beginning Algebra, 11th Edition

Decide whether each equation defines y as a function of x. (Remember that, to be a function,
every value of x must give one and only one value of y.)

Find the domain and the range for each function. See Example 4.

26.y=-x+ 3 27.ƒ 1 x 2 = 1 x 28.ƒ 1 x 2 =|x|

y= 3 x- 2 y=x^2 - 3 y=x^2 + 2

y=- 3 x^2 x=y^2 x=|y|

y= 5 x+ 3 y=- 7 x+ 12 y=x^2

SECTION 3.6 Introduction to Functions 235

9. 10.

B

A

C

D

E 4

(^36)
2
Domain Range
4
2
8
6
(^10) –8
–6
–2 –3
–1
Domain Range

11. 12. 13.

14. 15. 16.

y

0 x

2

2

y

0 x

2

(^2) x
y
0
x
y
0 x
y
0
x
y
0
EXERCISES 29–32
FOR INDIVIDUAL OR GROUP WORK
A function defined by the equation of a line, such as
is called alinear function.It can be graphed by replacing with y and then using
the methods described earlier in this chapter. Let us assume that some function is writ-
ten in the form for particular values of m and b.Work Exercises
29–32 in order.
29.If name the coordinates of one point on the line.
30.If name the coordinates of another point on the line.
31.Use the results of Exercises 29 and 30to find the slope of the line.
32.Use the slope-intercept form of the equation of a line to write the function in the
form ƒ 1 x 2 =mx+b.
ƒ 1 - 12 =-4,
ƒ 122 =4,
ƒ 1 x 2 =mx+b,
ƒ 1 x 2
ƒ 1 x 2 = 3 x-4,

RELATING CONCEPTS