Question

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

Answer 1

just swap x and y, then make y the subject of the equation

so swapping you have

\[x = y^2 - 16\]

now make y the subject

Answer 2

\(\bf f(x)= x^2 - 16 \implies \color{red}{y} = \color{blue}{x}^2 - 16\\
f^{-1}(x)\implies \color{blue}{x} = \color{red}{y}^2 - 16\)