The function is $\"\"$ .

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

$\"\"$

Product rule of derivatives : $\"\"$ .

$\"\"$

Derivative of a sine function is : $\"\"$ .

Power rule of derivatives is $\"\"$ .

$\"\"$

$\"\"$ .

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

$\"\"$ .

$\"\"$

Derivative of a cosine function is : $\"\"$ .

$\"\"$

$\"\"$ .