$\"\"$

The function is $\"\"$ .

The definition of the function is $\"\"$ .

Find $\"\"$ .

$\"\"$ .

Apply derivative on each side with respect to $\"\"$ .

$\"\"$

Apply second derivative on each side with respect to $\"\"$ .

$\"\"$

Observe the function.

As $\"\"$ tends to $\"\"$ from left hand side, the function $\"\"$ approaches to $\"\"$ .

As $\"\"$ tends to $\"\"$ from right hand side, the function $\"\"$ approaches to $\"\"$ .

Therefore $\"\"$ does not exist at $\"\"$ .

$\"\"$ does not exist at $\"\"$ .