設(shè)有信號試求f1(t)f2(t)的頻譜函數(shù)
設(shè)有如下信號f(t),分別求其頻譜函數(shù) (1)f(t)=e-(3+j4)t·ε(t) (2)f(t)=ε(t)-ε(t-2)
設(shè)信號試求f2(t)=f1(t)cos50t的頻譜函數(shù),并大致畫出其幅度頻譜