Sin(pai-x)cos(2pai-x)tan(pai+x)+cos(pai-x)^2
问题描述:
Sin(pai-x)cos(2pai-x)tan(pai+x)+cos(pai-x)^2
Rt
答
sinxcos(-x)tanx+(cos(-x))^2
=sinxcosx*sinx/cosx+cos^2x
=sin^2x+cos^2x
=1