WillTeachMaths logo

WillTeachMaths

Thinking-first maths tools

Beyond A Level

A simple recurrence can behave in surprisingly complicated ways.

The logistic map starts with a familiar idea: repeatedly applying a formula. As the growth parameter changes, the sequence can settle, cycle or become chaotic.

This makes it a powerful bridge from A level sequences and iteration into university-style dynamical systems.

Iteration lab

Iterate one simple rule and watch the behaviour change

The logistic map is x_next = r x (1 - x). It can settle down, oscillate, or become chaotic depending on the value of r.

x_n over timeiteration n

r

3.720

Initial value

0.420

Long-run min

0.2436

Long-run max

0.9296

Bifurcation view

One parameter creates a whole landscape of behaviour

For each r-value, the diagram plots long-term values after the early iterations are ignored. Splitting branches suggest cycles; dense regions suggest chaotic behaviour.

Bifurcation diagramr = 2.5r = 4

Joy in the process

The point is not just to finish. It is to notice, test and return.

These tools are invitations to explore. A good mistake, a surprising pattern or a question you cannot yet answer is part of the work, not a failure of it.

The challenge is deliberate: the site should support thinking, not remove the need for it.

Before changing a setting, pause and predict what you think will happen.
Change one thing at a time. What stayed the same, and what changed?
Try to create a surprising case, a broken case, or a beautiful pattern.
Ask what this connects to outside the page: maps, movement, nature, systems or decisions.
Reset, then try again with a new question in mind.

Future extensions

This can become a richer chaos and dynamical systems lab.

Add cobweb diagrams to connect iteration with graph transformations.
Add challenge tasks for fixed points and stability.
Add side-by-side comparison for two starting values over more iterations.
Add links to population modelling and nonlinear systems.