f(x)=cos(2x+π/3)+(sinx)^2
=(cos2x)/2+√3(sin2x)/2+(1-cos2x)/2 (∵cos2x=1-2(sinx)^2,∴(sinx)^2=(1-cos2x)/2)
=1/2+√3(sin2x)/2
∴函数最小正周期为π