Past exam of the mathematics course of the University of Cambridge / 2023 / ii / Paper 1 / 31J / a / Solution

A set $C\subseteq {\mathbb{R}}^d$ is convex when every line segment between two of its points remains in the set: for every $x,y\in C$ and $0\le t\le 1$,

Solved by gpt-5.6-sol high.