$\"\"$

\

Method 1 :

\

The equation is $\"\"$ .

\

For any input of $\"\"$ , we get only one output for $\"\"$ .

\

An input $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

An input $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

For any input of $\"\"$ , we get only one output for $\"\"$ .

\

So, the equation $\"\"$ defines $\"\"$ as a function of $\"\"$ .

\

$\"\"$

\

Method 2 :

\

The equation is $\"\"$ .

\

There is no $\"\"$ sign when $\"\"$ is written explicitly in terms of $\"\"$ .

\

So, the equation $\"\"$ defines $\"\"$ as a function of $\"\"$ .

\

$\"\"$

\

The equation $\"\"$ defines $\"\"$ as a function of $\"\"$ .