Sequential derivatives
arXiv:1801.04039
Abstract
Consider a real valued function defined, but not differentiable at some point. We use sequences approaching the point of interest to define and study sequential concepts of secant and cord derivatives of the function at the point of interest. If the function is the celebrated Weierstrass function, it follows from some of our results that the set cord derivatives at any point coincides with the extended real line.
10 pages