Question

Find f(x) = x^2 - 81. Find f^-1(x)

Answer 1

1) Replace the \(\large\color{slate}{ f(x) }\) with \(\large\color{slate}{ y }\) .
2) Change the \(\large\color{slate}{ y }\) and \(\large\color{slate}{ x }\) with each other.
3) Solve the (new) function for \(\large\color{slate}{ y }\) .
4) (After solving for y) re-write the function, but instead of \(\large\color{slate}{ y }\), write \(\large\color{slate}{ f^{-1}(x) }\).