因为sin(x+π/2)=sin[π/2 - (-x)]=cos(-x)=cosx,cos(x+π/2)=cos[π/2 - (-x)]=sin(-x)=-sinx,所以：sinˆ6(x+π/2)+cosˆ6(x+π/2)=cos^6 x + (-sinx)^6=cos^6 x + sin^6 x=sin^6 x + cos^6 x