f(x)=-√3cos2x-sin2x=-2[(√3/2)cos2x+(1/2)sin2x]=-2cos(2x-π/6)
最小T=2π/2=π
x=π/12,f(π/12)=-2
x=π/3,f(π/3)=0
-2≤f(x)≤0
-π/3≤x≤π/12单调递减
π/12≤x≤π/3 单调增加