A.100HzB.150HzC.200HzD.400Hz
如圖所示信號(hào)x(t)的頻譜X(jω)等于()
A.j4Sa(ω)sinωB.j2Sa(ω)sin2ωC.j4Sa(ω)sin2ωD.4Sa(ω)cos2ω
信號(hào)的傅里葉變換等于()
A.B.C.D.