2sin（x＋π／6）－1＝＞0
sin(x+π/6)≥1/2
x+π/6∈[2kπ+π/6,2kπ+5π/6]
x∈[2kπ,2kπ+2π/3] k∈z
x的集合为
{x|x∈[2kπ,2kπ+2π/3] k∈z}