Math 2.0

Ordinary differential equations Definition

Equilibrium point

Builds on Autonomous systemSolution of an ordinary differential equation

Definition

Let UU be an open subset of ℝn\mathbb{R}^n and let f:U→ℝnf : U \to \mathbb{R}^n be a function. A point x∗∈Ux^* \in U is an equilibrium point of the autonomous system x′=f(x)x' = f(x) if f(x∗)=0f(x^*) = 0.

Remarks

The point x∗x^* is an equilibrium point exactly when the constant function x(t)=x∗x(t) = x^* is a solution. For the logistic equation x′=rx(1−x/K)x' = r x (1 - x/K) with r,K>0r, K > 0, the equilibrium points are 00 and KK. The equilibrium points are the fixed points of the flow: φt(x∗)=x∗\varphi_t(x^*) = x^* for each tt. The behaviour of solutions near an equilibrium point is the subject of Lyapunov stability.

Reading path

To understand this page from the ground up, read these 7 pages in order. The foundations come first.

Show the path as a graph
Each page uses the pages above it. The colour of the bar on a box shows how strong the evidence is, and the box also gives it as text. The list has the same pages.
  • no evidence level
  1. Differential equation concept
  2. Function concept
  3. Interval concept
  4. Ordinary differential equation definition
  5. Solution of an ordinary differential equation definition
  6. Autonomous system definition
  7. Equilibrium point definition

Where this leads

37 pages build on this one.

Further reading

  1. Web https://en.wikipedia.org/wiki/Equilibrium_point_(mathematics), Formal definition
About this page