如果f (t) ←→F(ω) ，则下列说法正确的是（ ）。
A: F(t) ←→ 2πf(–ω)
B: F(t) ←→ 2πf(ω)
C: F(t) ←→ f (-ω)
D: F(t) ←→ f(ω)
A: F(t) ←→ 2πf(–ω)
B: F(t) ←→ 2πf(ω)
C: F(t) ←→ f (-ω)
D: F(t) ←→ f(ω)
举一反三
- 【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)
- 周期T与频率f的关系为（） A: T=f B: T=1/f C: T=2πf D: T=2π/f
- 下列等式不成立的是_____。 A: f(t)δ’(t)=f(0)δ’(t) B: f(t)δ(t)=f(0)δ(t) C: f(t)*δ’(t)=f ’(t) D: f(t)*δ(t)=f(t)
- 针对程序段：IP(A||B||C) THEN W=W/X，对于(A,B,C)的取值，(57)测试用例能够满足MCDC(修正条件逻辑判定)的要求。 A．(F,T,T)(T,F,T)(T,F,F)(T,T,F) B．(T,F,F)(T,T,F)(F,T,T)(F,F,F) C．(T,F,F)(T,T,F)(F,T,T)(F,F,T) D．(T,F,F)(F,T,F)(F,F,T)(F,F,F)
- 如果()f()1()(t)()和()f()2()(t)()均为()周期信号(),()下列()对()信号()f()1()(t)()+()f()2()(t)()说法正确的是()。A.()一定是周期信号()B.()一定是()非()周期信号()C.()f()1()(t)()+()f()2()(t)()是否为周期信号，与()f()1()(t)()及()f()2()(t)()周期无关。()D.()若()f()1()(t)()和()f()2()(t)()周期()均为整数，则一定是()周期信号