Question

What is the inverse of the function f(x) = one-quarterx – 12?

Answer 1

`f^(-1)` (x) = 4x + 48

Explanation:

let y = f(x) and rearrange making x the subject, that is

y =
`(1)/(4)` x - 12 ( multiply through bt 4 to clear the fraction )

4y = x - 48 ( add 48 to both sides )

4y + 48 = x

Change t back into terms of x with x =
`f^(-1)` (x)

`f^(-1)` (x) = 4x + 48

Answer 2

y = 4x - 48

Explanation:

y = 1/4 x - 12

x = 1/4 y - 12

4x = y - 48

y = 4x - 48