（1）增区间：【2kπ，2kπ+π】减区间：【2kπ+π，2kπ+2π】；（2）增区间满足：2kπ-π/2≤1/2x-π/3≤2kπ+π/22kπ-π/6≤1/2x≤2kπ+5π/64kπ-π/3≤x≤4kπ+5π/3即增区间为【4kπ-π/3，4kπ+5π/3】同理减区间为：【4kπ+5π/3，4kπ+11π/3]
