Let $f(x) = 3x -1$
Can someone explain how to verify $f[f^{-1}(x)] = x$ and $f^{-1}[f(x)] = x$, each for $x$ in the appropriate domain?
I was able to determine that the inverse function of $f(x) = 3x - 1$ is $\frac {x + 1}{3}$.
Do I just substitute in the known equations and solve?