Homework 3 Part A

Time Invariant
A system is time invariant if the behavior and characteristics of the system are fixed over time.
For example:
y(t)=sin[x(t)] , is time invariant because if the input is shifted to the right by five and then ran through the system,
The output would be the same as if the shift had occurred after the input is ran through the system.
y(t-5)=sin[x(t-5)


Time variant
A system is time variant if the behavior and characteristics of the system are not fixed over time.
For example:
y(t)=x(2t) Let's say this function will compress y(t) by a factor of 2.
Applying a shift of 2 before the function is ran through the system ( y(t)=x(t-2) )
will result in a different graph then if the function is shifted after it is put through the system.

Alumni Liaison

Ph.D. on Applied Mathematics in Aug 2007. Involved on applications of image super-resolution to electron microscopy

Francisco Blanco-Silva