$\"\"$

\

The functions are $\"\"$ .

\

$\"open$

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

$\"open$

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$ (Substitute $\"\"$ )

\

$\"\"$

\

$\"\"$

\

$\"open$ , so the functions are inverse functions.