This article discusses the concept of differentiability in functions. It explains that a function is considered differentiable if its derivative exists at all points in its domain. The article specifically focuses on three types of points where a function is not differentiable – corners (or cusps), points of discontinuity, and points with vertical tangents. The article provides examples and graphs to illustrate these concepts.
source update: Differentiability of a Function Given its Graph – Towards AI