Solution
= Solution
A set is convex when it contains every segment joining two of its points. A <function> on a <convex set> is convex when
$$
f(tx+(1-t)y)\le tf(x)+(1-t)f(y)
$$
for all $x,y$ and $0\le t\le1$.
= Solution
A set is convex when it contains every segment joining two of its points. A <function> on a <convex set> is convex when
$$
f(tx+(1-t)y)\le tf(x)+(1-t)f(y)
$$
for all $x,y$ and $0\le t\le1$.