Convexity, concavity and inflection points

The second derivative describes the curvature of the graph: where $f''>0$ the function is convex ($\cup$), where $f''<0$ it is concave ($\cap$). The points at which the concavity changes are the inflection points, and they are found by looking for the zeros of $f''$ that make it change sign.

• Convexity, concavity and inflection points
• How to find inflection points