Step 1:

The equation is $\"image\"$ .

Using trigonometric multiple angle formula

$\"image\"$

$\"image\"$ $\"\"$

Apply zero product rule

$\"image\"$ and $\"image\"$ . $\"\"$

$\"image\"$ and $\"image\"$ .

The general solution of sine $\"image\"$ .

The general solution of cosine $\"image\"$ .

$\"image\"$ and $\"image\"$ .

Required solutions in the interval $\"image\"$ .

Hence, $\"image\"$ and $\"\"$ .

The solutions of equation in the interval $\"image\"$ are $\"image\"$ .

Solution:

The solutions of equation in the interval $\"image\"$ are $\"image\"$ .