Question

Question #3e1fb

Answer 1

Please refer to the explanation below for proof.

Explanation:

`LHS=sin^4x-cos^4x+cos^2x`

`=(sin^2x)^2-(cos^2x)^2+cos^2x`

`=(sin^2x+cos^2x)*(sin^2x-cos^2x)+cos^2x`

`=sin^2x-cos^2x+cos^2x=sin^2x=RHS`