Editing Time-variant system (section)

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A '''time-variant system''' is a [[system]] whose output response depends on moment of observation as well as moment of input signal application.<ref>{{Cite book|title=An Introduction to Parametric Digital Filters and Oscillators|last=Cherniakov|first=Mikhail|publisher=Wiley|year=2003|isbn=978-0470851043|pages=47–49}}</ref> In other words, a time delay or time advance of input not only shifts the output signal in time but also changes other parameters and behavior. Time variant systems respond differently to the same input at different times. The opposite is true for [[time-invariant system|time invariant]] systems (TIV).