y=sinx-√3cosx=2(sinx*cos60-cosx*sin60)=2sin(x-60)
-2<=y<=2
2k*pai-pai/6<=x<=2k*pai-2pai/3 增
2k*pai-2pai/3<=x<=2k*pai-5pai/3 减
y=sinx-√3cosx=2(sinx*cos60-cosx*sin60)=2sin(x-60)
-2<=y<=2
2k*pai-pai/6<=x<=2k*pai-2pai/3 增
2k*pai-2pai/3<=x<=2k*pai-5pai/3 减