English

Explicit formulas related to Euler's product expansion for cosine function

Number Theory 2024-07-30 v1

Abstract

In this paper, we derive by using elementary methods some continued fractions, certain identities involving derivatives of tanx, several expressions for log coshx and an identity for {\pi}2, from a series expansion of tan x, which gives the product expansion of the cosine function.

Keywords

Cite

@article{arxiv.2407.19885,
  title  = {Explicit formulas related to Euler's product expansion for cosine function},
  author = {Taekyun Kim and Dae San Kim},
  journal= {arXiv preprint arXiv:2407.19885},
  year   = {2024}
}

Comments

13 pages

R2 v1 2026-06-28T17:56:41.284Z