这个展开,降次就可以了啊
sin^6α+(1-sin²α)³
=sin^6α+1-3sin^2α+3sin^4α-sin^6α
=1-3sin^2α+3sin^4α
=1-3sin^2α(1-sin^2α)
=1-3sin^2α cos^2α
=1-3/4sin^2(2α)