函数y=sin[-(1/2)x+π/4]=sin{-[(1/2)x-π/4]}=-sin[(1/2)x-π/4]的单调区间解:单增区间:由2kπ+π/2≦(1/2)x-π/4≦2kπ+3π/2,得 2kπ+3π/4≦(1/2)x≦2kπ+7π/4,得单增区间为:4kπ+3π/2≦x≦4kπ+7π/2;单减区间:由2kπ-π/2≦(1/2)x-π/4≦2kπ+π/2.得 2kπ-π/4≦(1/2)x≦2kπ+3π/4,得单减区间为:4kπ-π/2≦x≦4kπ+3π/2;