Question

(sin)power4theta + (cos)power4theta + 2(sin)square theta multiply (cos)square theta = 1 .
Prove the following trigonometrical idedtities

Answer 1

I m going to use A in place of theta because it takes too much time Sin^4A + cos^4A + 2sin^2cos^2=1 [Sin^2A + Cos^2A ]^2 = 1 { and we know that sin^2theta+cos^2theta = 1] Therefore LHS = RHS Hence proved