cos(x+π/6)=cosxcosπ/6-sinxsinπ/6所以y=sinx(√3/2*cosx-1/2*sinx)-1/2*cos2x=√3/2*sinxcosx-1/2sin²x-1/2*cos2x=(√3/4)sin2x-1/2*(1-cos2x)/2-1/2*cos2x=(√3/4)sin2x-1/4*cos2x+1/4=√(3/16+1/16)sin(2...