Question

Let f(x) = 2x + 2, how do you solve `f^-1(x)` when x = 4?

Answer 1

One.

Explanation:

Exchange x and y and the inverse is `x = 2y + 2`

`x - 2 = 2y => y = x/2 - 1 = f^-1(x)`

`f^-1(4) = 4/2 - 1`