f(x) =2sin(x-π/6)cosx+2cos²x=2(sinxcosπ/6-cosxsinπ/6)cosx+2cos²x=√3sinxcosx+(cosx)^2=(√3/2)*sin2x+(cos2x+1)/2=(√3/2)*sin2x+(1/2)*cos2x+1/2=sin(2x+π/6)+1/2单调递增区间：2kπ-π/2...