The function is $\"\"$ .

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

$\"\"$

Apply the mean value theorem.

$\"\"$

$\"\"$ .

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

$\"\"$

The interval is $\"\"$ which does not include $\"\"$ .

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 discontinuous at $\"\"$ .