The behaviour of a linear autonomous system around a critical point is a node if the following conditions are satisfied: Each path converges to or away from the critical point (dependent of the underlying equation) as t → ∞ {\displaystyle t\rightarrow \infty } (or as t → − ∞ {\displaystyle t\rightarrow -\infty } ). Furthermore, each path approaches the point asymptotically through a line.
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