Answer:
sin ^2 x+ cos ^2 x = 1
Explanation:
sin^2 x - cos ^2 x sin ^2 x = sin ^4 x
Factor sin^2 x
sin ^2 x ( 1- cos ^2 x ) = sin ^4 x
Using the identity sin ^2 x+ cos ^2 x = 1 written as 1 -cos ^2 x = sin ^2 x
sin ^2 x ( sin^2 x ) = sin ^4 x
sin ^4 x = sin ^4 x