$\"\"$

The equation $\"\"$ .

Solve for $\"\"$ .

$\"\"$

$\"\"$ .

We see that there is a $\"\"$ sign when $\"\"$ is written explicitly in terms of $\"\"$ .

So, the equation $\"\"$ does not defines $\"\"$ as a function of $\"\"$ . $\"\"$

The equation $\"\"$ is not a function.