f(x)=(1-cos2x)/2-(sin2xcosπ/6-cos2xsinπ/6)
=1/2-1/2·cos2x-√3/2·sin2x+1/2·cos2x
=1/2-√3/2·sin2x
∴最小正周期T=2π/2=π,最大值1/2+√3/2