$\"\"$

Find the derivative of the function $\"\"$ .

Rewrite the above function $\"\"$ .

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

$\"\"$ .

Derivative of inverse tangent function : $\"\"$ .

Chain rule of derivative: $\"\"$ .

$\"\"$

The derivative of cosine function : $\"\"$ .

$\"\"$

$\"\"$ .