Question

cos^{4} - sin^{4} = cos^{2} - sin^{2}

Answer 1

L=(cos²α+sin²α)(cos²α-sin²α)=1*cos²α-sin²α=P

L=P

Answer 2

L = cos^4(x) - sin^4(x) = [cos^2(x) + sin^2(x)]*[cos^2(x) - sin^2(x)] =cos^2(x) - sin^2(x)

          sin^2(x) + cos^2(x) = 1

P = cos^2(x) - sin^2(x)

L = P