$\"\"$

If $\"\"$ has an inverse function.

Then $\"\"$ .

Apply inverse of the function.

$\"\"$ , then $\"\"$ .

Therefore $\"\"$ is an one-to-one, for every value $\"\"$ in the range, there corresponds to exactly one value $\"\"$ in the domain.

The domain of $\"\"$ equals the range of $\"\"$ , then $\"\"$ .

The reflective property of inverse $\"\"$ .

Consider $\"\"$ .

Therefore, The inverse function is $\"\"$ .

$\"\"$

The inverse function is $\"\"$ .