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

transforms

Superposition and the general series solution

taught

Taught in

Superposition and the general series solution
Ordinary Differential Equations

Requires

separation-of-variables-first-look-toward-pdes required
expanding-a-function-in-a-sturm-liouville-eigenbasis required

Required by

Computing the sine-series coefficients for a separated heat-equation solution required

Local knowledge map

Local knowledge map

Click to expand

Solid arrows are required prerequisites; dashed are recommended or helpful. Lower rows are more foundational. Click any box to jump to that concept.