Question

If f(x) = 2x + 7, find f -1(x).f -1(x) = x - 7f -1(x) = (x - 7)/2f -1(x) = (x + 7)/2f -1(x) = x + 7

Answer 1

f-1(x) = (x-7)/2

In order to find the inverse of a function, reverse the equation

Let's say f-1(x) = y (to keep it as a go to, but I use it to make it simpler to see the steps )

y = 2x+ 7

y - 7 = 2x

(y - 7) / 2 = x

=> f-1(x) = (x - 7) / 2

NB:

The idea is to "revert" the arithmetic of the equation