Answer
If it passes the horizontal line test, the function has an inverse.
Work Step by Step
If the graph is that of a function, it means that it has passed the vertical line test.
In order to have an inverse, it has to be one-on-one.
It now needs to pass the Horizontal Line Test:
If every horizontal line intersects the graph of a function at most once, then the function is a one-to-one function.
