$\"\"$

\

The function is $\"\"$ .

\

Consider $\"\"$ .

\

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

\

$\"\"$ .

\

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

\

$\"\"$

\

Sum rule of cosine function: $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

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

\

$\"\"$ .

\

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

\

$\"\"$

\

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

\

$\"\"$

\

Sum rule of sine function: $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .