2x+4/π=2kπ+π/2 ,x=kπ+π/4-2/π函数取得最大值32x+4/π=2kπ-π/2 ,x=kπ-π/4-2/π函数取得最小值-31/2x+π/3=2kπ+π/2 ,x=4kπ+π/3函数取得最大值1/21/2x+π/3=2kπ-π/2 ,x=4kπ-5π/3函数取得最小值-1/2
