Memory Less

-DEFINITION: A System is memory less if and only if for any $ t_o $ (in the set of all REAL #'s), the output [y($ t_o $)] depends only on the input [x($ t_o $)].

  • i.e. If $ \bar{x} $(t) is equal to x(t) at t = $ t_o $, then $ \bar{y} $($ t_o $) = y($ t_o $)

-A System is memoryless if and only if output y(t) depends on PRESENT values of x(t).

Examples:

  • y(t) = x(t) + x(t-1)...... is NON MEMORYLESS.
  • y(t) = 2x(t).............. is MEMORYLESS b/c it depends only on present values of "t".
  • y(t) = x(t+1)............. is NON MEMORYLESS.
  • y(t) = (t+1) + x(t)....... is MEMORYLESS b/c "(t+1)" has no effect on x(t).
  • y[n] = x[n-1]............. is NON MEMORYLESS.

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Basic linear algebra uncovers and clarifies very important geometry and algebra.

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