State variable

A state variable is one of the set of variables that are used to describe the mathematical "state" of a dynamical system. Intuitively, the state of a system describes enough about the system to determine its future behaviour in the absence of any external forces affecting the system. Models that consist of coupled first-order differential equations are said to be in state-variable form.^[1]

^ Palm, III William J. (2009). System Dynamics (2nd ed.). McGraw-Hill Medical Publishing. p. 420. ISBN 978-0-07-126779-3.

[1] Palm, III William J. (2009). System Dynamics (2nd ed.). McGraw-Hill Medical Publishing. p. 420. ISBN 978-0-07-126779-3.

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