Question

(1-Cos2a)×(1-Cos2a)-3Sin2a

Answer 1

$(1 - \cos(2 \alpha ) (1 - \cos(2 \alpha ) - 3 \sin(2 \alpha ) = (1 - 1 + \ 2sin {}^{2} ( \alpha ) ) {}^{2} - 6 \sin( \alpha ) \cos( \alpha ) = 4 { \sin }^{2} \alpha - 6 \sin( \alpha ) \cos( \alpha )$