The function is $\"\"$ , $\"\"$

Differentiate $\"\"$ on each side with respect to $\"\"$ .

$\"\"$

$\"\"$ .

Substitute $\"\"$ in above expression.

$\"\"$

Apply the mean value theorem.

$\"\"$

$\"\"$ .

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

$\"\"$

Thus, there is no value $\"\"$ , such that $\"\"$ .

It does not contradict the mean value theorem because the function is discontinuous at $\"\"$ thus it does not differentiable in the given interval.

The function $\"\"$ is not differentiable at $\"\"$ .