sin(ωx)-cos(ωx)=√2[sin(ωx)*√2/2-cos(ωx)*√2/2)] --------利用√2*√2/2=1进行变形=√2[sin(ωx)*cosπ/4-cos(ωx)*sinπ/4)]--------[sinπ/4=cosπ/4=√2/2]进行代换=√2sin(ωx-π/4)-----正弦函数二角差公式即sin(ωx)-cos(ωx)=√2sin(ωx-π/4)
