f(x)=√3sin(x/2)cos(x/2)＋cos²(x/2)－(1/2)
=(√3/2)sinx＋(1/2)cosx
=sin(x＋π/6)
增区间是：2kπ－π/2≤x＋π/6≤2π＋π/2
增区间是：[2kπ－2π/3,2kπ＋π/3]k∈Z