We're talking all about stability >[!note] Autonomous vs. Nonautonomous Systems >**Autonomous**: $\dot x = X(x)$ >**Non-Autonomous:** $\dot x = X(x,t)$ We talk about stability usually meaning that things settle to an equilibrium point. But this isn't the only way to look at things... # Poincare Stability (Path Stability) For autonomous systems. Basically, adhere to a path for distrubances. ## Types of Paths ### Standard Path $x^*$ is a phase path or equilibrium point whose stability is in question. This is a solution of $\dot x = X$ ### 'Half-path' or 'Half-orbit' or 'Semi-orbit'