f（x）＝2sin（x－丌/3）cosx
=2(sinxcosπ/3-cosxsinπ/3)cosx
=2(1/2sinx-√3/2cosx)cosx
=sinxcosx-√3cos²x
=1/2·sia2x-√3·(cos2x+1)/2
=1/2·sia2x-√3/2cos2x-√3/2
=sin(2x-π/3)-√3/2
∴ω=2
∴T=2π/2=π
最小正周期是π.