Question

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

Answer 1

For this case we have that by definition, the domain of a function is given by all the values for which the function is defined.

While the range of the function is the set of all the values that $f (x)$ takes.

We have the following function:

$f (x) = 4x + 9$

We evaluate in the domain:

$f (-4) = 4 (-4) + 9 = -16 + 9 = -7\\f (-2) = 4 (-2) + 9 = -8 + 9 = 1\\f (0) = 4 (0) + 9 = 0 + 9 = 9\\f (2) = 4 (2) + 9 = 8 + 9 = 17$

ANswer:

{-7,1,9,17}