f(x)＝2sin(x-pi/6)sin(x＋pi/3) 求最小正周期

f(x)＝2sin(x-π/6)sin(x＋π/3)=(√3sinx-cosx)(1/2sinx+√3/2cosx)
=√3/2sin^2x+sinxcosx-√3/2cos^2x=-√3/2cos2x+1/2sin2x=sin(2x-π/3)
最小正周期T=π