Step 1:

\

The function is $\"\"$ .

\

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

\

$\"\"$

\

Apply the trigonometry function of derivative: $\"\"$ .

\

$\"\"$ ..

\

Newtons method:

\

$\"\"$

\

Step 2:

\

$\"\"$

\

Find $\"\"$

\

$\"\"$

\

$\"\"$

\

Find $\"\"$

\

$\"\"$

\

$\"\"$

\

Solution :

\

$\"\"$

\

$\"\"$