Question

What is the range of the function f(x) = 4x + 9, given the domain D = {-4, -2, 0, 2}?

A.
R = {-17, -9, -1, 17}
B.
R = {-7, -1, 9, 17}
C.
R = {-7, 1, 9, 17}
D.
R = {1, 7, 9, 17}

Answer 1

Option C. the range is {-7, 1, 9 , 17} Option C

Answer 2

f(x) = 4x+9

At x=-4

f(-4) = 4(-4) +9 = -16 +9 = -7

At x=-2

f(-2) = 4(-2) +9 = -8+9 = 1

At x= 0

f(0) = 4(0) + 9 = 9

At x= 2

f(2) = 4(2) +9 = 8+9 = 17

So the range is {-7, 1, 9 , 17} , i.e. Option C