English

A Fundamental Theorem of Calculus for Second-order Directional Derivative

Classical Analysis and ODEs 2023-08-28 v2 Differential Geometry

Abstract

Given a two-variable function ff without critical points and a compact region RR bounded by two level curves of ff, this note proves that the integral over RR of the second-order directional derivative of ff in the tangential directions of the interceding level curves is proportional to the rise in ff-value over RR. Also discussed are variations on this result when critical points are present or RR becomes unbounded.

Keywords

Cite

@article{arxiv.2107.11038,
  title  = {A Fundamental Theorem of Calculus for Second-order Directional Derivative},
  author = {Pisheng Ding},
  journal= {arXiv preprint arXiv:2107.11038},
  year   = {2023}
}