sinxcosx+cosx^2-2 化简
问题描述：
sinxcosx+cosx^2-2 化简
答
sinxcosx+cosx^2-2
=(1/2)*2sinxcosx+(1/2)*[2*(cosx)^2-1]-(3/2)
=(1/2)sin2x+(1/2)cos2x-(3/2)
=(√2/2)sin(2x+π/4)-(3/2)