y=sin2x*1/2-cos2x*√3/2-sin2x=-(1/2)sin2x-(√3/2)*cos2x=-[(1/2)sin2x+(√3/2)*cos2x]=-√(1/4+3/4)sin(2x+z)=-sin(2x+z)其中tanz=(√3/2)/(1/2)=√3z=π/3-sin(2x+π/3)的增区间即sin(2x+π/3)的减区间sinx的减...