Calculus 10th Edition

$f(x)$ has an inverse function.
We find the derivative of $f(x)$: $f'(x) = \frac{1}{x-3} , x \gt; 3$ We see that on the domain of $f(x)$, $(3, \infty)$, $f'(x)$ is always positive so $f(x)$ is strictly monotonic.