Solution
= Solution
A <convex function> satisfies
$$
\boxed{F((1-t)x+ty)\leq(1-t)F(x)+tF(y)\quad(x,y\in\mathbb R^n,\ 0\leq t\leq1).}
$$
Thus its value on every <line segment> lies below the chord joining the endpoint values.
= Solution
A <convex function> satisfies
$$
\boxed{F((1-t)x+ty)\leq(1-t)F(x)+tF(y)\quad(x,y\in\mathbb R^n,\ 0\leq t\leq1).}
$$
Thus its value on every <line segment> lies below the chord joining the endpoint values.