• 2022-06-11
    已知f1(t)=u(t+1),f2(t)=u(t+2)-u(t-2),设y(t)= f1(t)* f2(t),则y(0)等于()
    A: 0
    B: 1
    C: 2
    D: 3
  • D

    内容

    • 0

      设f1(t)=2[u(t一7)一u(t一1)],f2(t)=0.5[u(t一5)一u(t一2)]。用图解法求s(t)=f1(t)*f2(t)。

    • 1

      【多选题】若f 1 (t) = ɛ (-t) , f 2 (t) = e t ,则f 1 (t)* f 2 (t) = A. f 1 ꞌ (t)* f 2 (–1) (t) B. f 1 (–1) (t)* f 2 ꞌ (t) C. f 1 (t-3)* f 2 (t+3) D. f 1 (–3) (t)* f 2 ꞌꞌꞌ (t)

    • 2

      已知系统传输算子为H(p)=(p+3)/[p2+3p+2],并知y(0)=1,y’(0)=2,求以下输入的全响应:(1) f(t)=u(t),(2) f(t)=e-3tu(t)

    • 3

      设f(1)=0,t<3,试确定信号f(1-1)+f(2-t)为0的t值 A: t>-2或t>-1 B: t=1或t=2 C: t>-1 D: t>-2

    • 4

      已知f1(t)=u(t+1)-u(t-1),f2(t)=u(t-1)-u(t-2),则f1(t)*f2(t)的非零值区间为(0,3)