y=3sin(2x+π/3)的最小值为-3,最大值为3,单调增区间为[Kπ-5π/12,Kπ+π/12]减区间为[Kπ+π/12,Kπ+7π/12]分析：y=sinx最小值为-1,最大值为1,单调增区间[2Kπ-π/2,2Kπ+π/2],单调减区间[2Kπ+π/2,2Kπ+3π/2]...