y=sin(2x+30°)-cos(2x+60°) =sin2xcos30+sin30cos2x-(cos2xcos60-sin2xsin60) =√3sin2x/2+cos2x/2-cos2x/2+sin2x√3/2 =√3sin2xT=2兀/2=兀最大值√3=1.732B
B