Cos^4a-sin^4a+sin^2a=?

Question

Cos^4a-sin^4a+sin^2a=?

Answer 1

cos^4a-sin^4a+sin^2a=(cos^2a-sin^2a)(cos^2a+sin^2a)+sin^2a=cos^2a-sin^2a+sin^2a=cos^2a