Question

Let f(x) = x2 - 16. Find f-1(x).

Answer 1

Let\[f(x) = y \]and\[y = x \]This becomes:\[x = y^2 - 16 \]Solve for \(y\) in terms of \(x\).

Answer 2

find x in terms of f(x)
replace f(x) by x
- and you have f-1(x)