楼主你好sin(x+π/4)=sinxcosπ/4+cosxsinπ/4=(√2/2)×(sinx+cosx)所以[sin(x+π/4)]^2=(1/2)×[(sinx)^2+2sinxcosx+(cosx)^2]=(1/2)×(1+sin2x)希望你满意
sin(x+45度）的平方= (1- cos(2x + 90度))/2 = 1/2 + (1/2)sin2x
