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Memoryless System

A memoryless system is a system for which for any real number $ t_0 $, the output at $ t_0 $ depends only on that value of t.

A system with memory is a system whose output depends on the value $ t_0 $ as well as another value of t for any given $ t_0 $

Causal System

A system is causal if the output at any given time only depends on the input in present and past (not the future)

A system is not causal if the output at any given time depends on input in the future.

Linear System

A system is linear if for any complex constants a and b and for any inputs $ x_1(t) and x_2(t) $ yielding output $ y_1(t) and y_2(t) $ respectively, the response is $ a*x_1(t)+b*x_2(t) ==> [SYSTEM] ==> a*y_1(t) + b*y_2(t) $


1- Give a formal definition of a “memoryless system”. Give a formal definition of a “system with memory”.

2- Give a formal definition of a “causal system”. Give a formal definition of a non-causal system.

3- Give a formal definition of a “linear system”. Give a formal definition of a “non-linear system”.

4- Give a formal definition of a “time invariant system”. Give a formal definition of a “time variant system”.

5- Give a formal definition of a “stable system”. Give a formal definition of an unstable system.

Alumni Liaison

Abstract algebra continues the conceptual developments of linear algebra, on an even grander scale.

Dr. Paul Garrett