3脉动系数s S 2 π23π4πat √2=2=1.57 2 设f(x)是以2m为周期的函数,且能展开成三角级数,即有 f(x)=+>(ancon +b n Sinn) f(t)=A+∑A im cos(k t+ 2) :5S:353.脉动系数S oim o U S U = uo π 2π 3π 4π ωt Uo 2 2 2 2 2 1.57 2 2 oim oim o U U U U S U U   = = = = = 设f(x)是以2π为周期的函数，且能展开成三角级数，即有