English

A generalization of an identity due to Kimura and Ruehr

Number Theory 2017-06-28 v1

Abstract

An identity stated by Kimura and proved by Ruehr, Kimura and others stipulates that for any function ff continuous on [12,32][-\frac{1}{2}, \frac{3}{2}] one has 1/23/2f(3x22x3)dx=201f(3x22x3)dx. \int_{-1/2}^{3/2} f(3x^2 - 2x^3) dx = 2 \int_0^1 f(3x^2 - 2x^3) dx. We prove that this equality is not an isolated example by providing a family of polynomials, related to the Tchebychev polynomials and of which (3x22x3)(3x^2 - 2x^3) is a particular case, giving rise to similar identities.

Keywords

Cite

@article{arxiv.1706.08929,
  title  = {A generalization of an identity due to Kimura and Ruehr},
  author = {Jean-Paul Allouche},
  journal= {arXiv preprint arXiv:1706.08929},
  year   = {2017}
}