Find the inverse function of f(x)=3^x

Question

Inverse functions formula

Answer 1

Let y=f(x)=3^x, and take logs to base 3 of each side then log[3]y=x, or x=log[3]y. The inverse function is g so that x=g(y). Therefore the inverse function g(x)=log[3]x.

Example: g(81)=4 and f(4)=81.