展开
sin^2α+cosαcos(π/3+a)-sin^2(π/6-α)
=(sinα)^2+cosα[1/2×cosα-√3/2×sinα]+[1/2×cosα-√3/2×sinα]^2
=(sinα)^2+1/4×(cosα)^2-3/4×(sinα)^2
=1/4×(sinα)^2+1/4×(cosα)^2
=1/4
展开
sin^2α+cosαcos(π/3+a)-sin^2(π/6-α)
=(sinα)^2+cosα[1/2×cosα-√3/2×sinα]+[1/2×cosα-√3/2×sinα]^2
=(sinα)^2+1/4×(cosα)^2-3/4×(sinα)^2
=1/4×(sinα)^2+1/4×(cosα)^2
=1/4