Step 1:

The trigonometric identity is $\"\"$ .

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

Rewrite the identity $\"\"$ .

Double Angle Formula for trigonometric identitites: $\"\"$ .

Substitute in the trigonometric identity.

$\"\"$

Fundamental identities: $\"\"$ .

$\"\"$

Double Angle Formula for trigonometric identitites: $\"\"$ . \ \

$\"\"$

Double Angle Formula for trigonometric identitites: $\"\"$ .

$\"\"$

= Right hand side identity.

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

$\"\"$ .

Solution:

$\"\"$ .