• Support PF! Buy your school textbooks, materials and every day products Here!

Time invariance. Proof help

  • Thread starter ttttrigg3r
  • Start date
  • #1
49
0

Homework Statement



y(n)=x(4n+1). Is this system T.I or NOT T.I

The professor marked this question wrong for my homework. He says it's NOT time invariant. I proved it is time invariant.


Homework Equations



System is time invariant if a shift in time in input results in the same shift in time when the output is shifted.

The Attempt at a Solution


shift in the x:
y1=x(4(n-n0)+1)
y2=shift in y=y(n-n0)=x(4(n-n0)+1)

They are the same, therefore they system is time invariant.
The professor marked this problem wrong for me, and he gave me the run-around when I asked for him to prove it. Did I do this right?
 

Answers and Replies

  • #2
UltrafastPED
Science Advisor
Gold Member
1,912
216

Related Threads on Time invariance. Proof help

  • Last Post
Replies
0
Views
724
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
1
Views
6K
  • Last Post
Replies
1
Views
825
  • Last Post
Replies
1
Views
720
  • Last Post
Replies
1
Views
5K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
1
Views
8K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
2K
Top