Definition:Point of Inflection/Definition 1

Definition

Let $f$ be a real function which is differentiable on an interval $\Bbb I \subseteq \R$.

Let $\xi \in \Bbb I$.

$f$ has a point of inflection at $\xi$ if and only if $\xi$ is a point on $f$ at which $f$ changes from being concave to convex, or vice versa.

Also see

• Equivalence of Definitions of Point of Inflection

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): inflection
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): inflection