设:两信号f1(t)和f2(t)如图。则:f1(t)和f2(t)间的关系为()
A: f(t)=f(t-2)ε(t-2)
B: f(t)=f(t+2)ε(t+2)
C: f(t)=f(2-t)ε(2-t)
D: f(t)=f(2-t)ε(t+2)
A: f(t)=f(t-2)ε(t-2)
B: f(t)=f(t+2)ε(t+2)
C: f(t)=f(2-t)ε(2-t)
D: f(t)=f(2-t)ε(t+2)
举一反三
- 设:两信号f1(t)和f2(t)如图。则:f1(t)和f2(t)间的关系为()。 A: f2(t)=f1(t-2)ε(t-2) B: f2(t)=f1(t+2)ε(t+2) C: f2(t)=f1(2-t)ε(2-t) D: f2(t)=f1(2-t)ε(t+2)
- 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
- 【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)
- f(t)为原始信号,f1(t)为变换信号,则f1(t)的表达式是( )。[img=722x219]17de73b5129ea9f.png[/img] A: f(t/2 + 1) B: f(-t/2 - 1) C: f(-2t+1) D: f(-t/2 + 1)
- f(t)为原始信号,f1(t)为变换信号,则f1(t)的表达式是( )。[img=722x219]1803709447eacc9.png[/img] A: f(t/2 + 1) B: f(-t/2 - 1) C: f(-2t+1) D: f(-t/2 + 1)