y=-3sin(2x-π/3)-π/2+2kπ＜2x-π/3＜π/2+2kπ -π/12+kπ＜x＜5π/12+kπ单调减区间（-π/12+kπ,5π/12+kπ）k∈Zπ/2+2kπ＜2x-π/3＜3π/2+2kπ5π/12+kπ＜x＜11π/12+kπ单调增区间(5π/12+kπ,11π/12+kπ...