## College Algebra (11th Edition)

$f^{-1}(4)=4$
The inverse of a function differs from the original function in that all the x-coordinates and y-coordinates have been switched. To find the value of $f^{-1}(4)$, we have to find the corresponding x-coordinate to $y=4$ in the original $f(x)$ function. We can see that in the graph of $f(x)$, when$y=4$, then $x=4$. Therefore $f^{-1}(4)=4$.