$\"\"$

The function is $\"\"$ .

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

$\"\"$ .

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

$\"\"$ .

Newtons method:

$\"\"$ .

Substitute $\"\"$ .

$\"\"$ .

$\"\"$

The value of $\"\"$ .

Find $\"\"$ .

$\"\"$

$\"\"$ .

Find $\"\"$

$\"\"$

$\"\"$ .

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

$\"\"$

$\"\"$ .