## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

The range of the inverse is $[4, \infty)$.
We know that the function and its inverse have the $x$ and $y$ interchanged. Thus, the domain of the one-to-one function is the range of its inverse function and vice versa. Therefore, the range of the inverse is: $[4, \infty)$.