Question

Verify sin4 x- sin2x = cos4x – cos2x is an identity

Answer 1

Explanation:

sin⁴ x − sin² x

Factor:

(sin² x) (sin² x − 1)

Pythagorean identity:

(1 − cos² x) (-cos² x)

Distribute:

-cos² x + cos⁴ x

cos⁴ x − cos² x