Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

learning rate

The fixed positive number $\eta$ in the update rule that sets how big each step is; too small and training crawls, too large and it can diverge.

Examples

With $\eta=1.1$ on $L(w)=(w-3)^2$ , $w$ jumps $0, 6.6, -1.32, 8.184, \ldots$ , growing farther from the minimum every step.