y=asin(ωx+φ)y=sinx的单调区间：2kπ-π/22kπ+π/2∴a>0时：2kπ-π/2<ωx+φ<2kπ+π/2→(2kπ-π/2-φ)/ω2kπ+π/2<ωx+φ<2kπ+3π/2→(2kπ+π/2-φ)/ω（默认ω>0）a<0时,正好相反(2kπ-π/2-φ)/ω(2kπ+π/2-φ)/ω
