Step 1:

The trigonometric identity is $\"\"$ .

Consider left hand side identity $\"\"$ .

Rewrite the identity

$\"\"$

Addition formula for trigonometric identitites:

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

Substitute in the trigonometric identity.

$\"\"$

Divide numerator and denominator by $\"\"$ .

$\"\"$

Fundamental identities : $\"\"$ .

$\"\"$

= Right hand side identity.

Hence, Left hand side identity is equal to Right hand side identity.

$\"\"$ .

Solution:

$\"\"$ .