king.carolyn53
king.carolyn53 3d ago • 1 views

Printable exercises on limit cycles and the Poincaré-Bendixson Theorem

Hey! 👋 Need some practice with limit cycles and the Poincaré-Bendixson Theorem? I've got a worksheet to help you nail down the concepts. Let's get started! 🤓
🧮 Mathematics

1 Answers

✅ Best Answer

📚 Topic Summary

Limit cycles are isolated closed trajectories in the phase plane of a dynamical system. They represent self-sustained oscillations, meaning the system will repeatedly cycle through the same states. The Poincaré-Bendixson Theorem provides a powerful tool for proving the existence of limit cycles in two-dimensional dynamical systems. Specifically, it states that if a trajectory remains confined within a bounded region of the plane that contains no fixed points, then the trajectory must approach a limit cycle.

Understanding limit cycles and the Poincaré-Bendixson Theorem is crucial for analyzing the long-term behavior of many systems, from electrical circuits to ecological models. These concepts help us predict and understand stable oscillatory behavior.

🧠 Part A: Vocabulary

Match the term with its correct definition:

Term Definition
1. Limit Cycle A. A point where the vector field is zero.
2. Trajectory B. A region in the phase plane where all trajectories move inward.
3. Fixed Point C. An isolated closed trajectory in phase space.
4. Phase Plane D. The path of a system's state through time.
5. Invariant Region E. A two-dimensional space where the axes represent the state variables.

📝 Part B: Fill in the Blanks

Complete the following paragraph with the correct terms:

The Poincaré-Bendixson Theorem applies to _______________ dynamical systems. It states that if a _______________ remains within a bounded region containing no _______________, then it must approach a _______________. This theorem helps prove the _______________ of self-sustained oscillations.

💡 Part C: Critical Thinking

Consider a system described by the following differential equations:

$\frac{dx}{dt} = y + x(1 - x^2 - y^2)$

$\frac{dy}{dt} = -x + y(1 - x^2 - y^2)$

Explain how you might use the Poincaré-Bendixson Theorem to show that this system has a limit cycle. What steps would you take, and what conditions would need to be satisfied?

Join the discussion

Please log in to post your answer.

Log In

Earn 2 Points for answering. If your answer is selected as the best, you'll get +20 Points! 🚀