Interactive lectures

Prototype. Narrated or silent, with endless practice you can check yourself, a writing pad and a calculator. Everything you type stays in your browser.

Prototype: the mathematics has not yet been reviewed by a human mathematician. Not an official programme: no qualification, mark or certificate is issued. English only for now.

The ε–δ game: what a limit really says
Real analysis · about 40 minutes · narrated · three paces
You play a game against an adversary, then turn it into a proof. Endless practice with a checker that tells you the exact input that beats your answer. Every matrix is a rotation, a stretch and a rotation
Linear algebra · about 45 minutes · silent
Drag a matrix, watch a circle become an ellipse, rebuild a picture from a few numbers, then prove where the singular values come from.

For teachers: read progress codes

Students can copy a progress code at the end of a lecture. Paste codes here, one per line. Nothing is sent anywhere: the codes are decoded in this browser.