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

Step-by-step 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

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^