$\"\"$

The function is $\"\"$ .

Take logarithm on each side.

$\"\"$

Product property of logarithms : $\"\"$ .

$\"\"$

Power property of logarithms : $\"\"$ .

$\"\"$ .

$\"\"$

$\"\"$ .

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

$\"\"$

Substitute $\"\"$ in the above equation.

$\"\"$

$\"\"$ .