Pompeiu derivative

The Pompeiu derivative is a concept from the field of mathematical analysis, specifically in the study of functions and their differentiability. It is defined through the idea of a limit, similar to the conventional derivative but under different conditions. For a function \( f: \mathbb{R} \to \mathbb{R} \), the Pompeiu derivative at a point \( a \) is defined using the average rate of change over smaller neighborhoods around \( a \).