strictly convex function
A convex function whose chord between two distinct points touches the graph only at its own two endpoints, never in between.
f is strictly convex on a convex set C if, for every x\ne y in C and every \theta\in(0,1), f(\theta x+(1-\theta)y)<\theta f(x)+(1-\theta)f(y) -- Section 4's inequality with equality ruled out whenever the two points genuinely differ. A strictly convex function has at most one global minimizer: two tied minimizers would force a flat chord between them, which the strict inequality disallows.
Point table
Graph settings
Calculator