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==Strongly convex functions==
The concept of strong convexity extends and parametrizes the notion of strict convexity. Intuitively, a strongly-convex function is a function that grows as fast as a quadratic function.<ref>{{Cite web |title=Strong convexity · Xingyu Zhou's blog |url=https://xingyuzhou.org/blog/notes/strong-convexity |access-date=2023-09-27 |website=xingyuzhou.org}}</ref> A strongly convex function is also strictly convex, but not vice versa. If a one-dimensional function <math>f</math> is twice continuously differentiable and the ___domain is the real line, then we can characterize it as follows:
*<math>f</math> convex if and only if <math>f''(x) \ge 0</math> for all <math>x.</math>
*<math>f</math> strictly convex if <math>f''(x) > 0</math> for all <math>x</math> (note: this is sufficient, but not necessary).
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