mathematics
2 free lessons tagged mathematics across Math. Each one is a short sequence of focused steps with narration and a five-question quiz at the end — take them in any order, no signup required.
Convexity: the property that decides what is solvable
Convexity is what separates optimization problems you can solve with a guarantee from ones you can only hope about. This lesson defines convex sets and functions, proves why every local minimum is global, and gives you the operations that let you recognise convexity without touching a Hessian.
What a Group Is, and Why the Axioms Are So Bare
A group is a set with one operation obeying four rules, and that deliberate poverty is the point: anything proved about groups holds for rotations, permutations, integers, XOR and Rubik's cube at once. This lesson builds the definition from symmetry, works through the symmetries of a square, and shows where groups already sit in code.