English

On a problem inspired by Descartes' rule of signs

Classical Analysis and ODEs 2024-08-22 v1

Abstract

We study real univariate polynomials with non-zero coefficients and with all roots real, out of which exactly two positive. The sequence of coefficients of such a polynomial begins with mm positive coefficients followed by nn negative followed by qq positive coefficients. We consider the sequence of moduli of their roots on the positive real half-axis; all moduli are supposed distinct. We mark in this sequence the positions of the moduli of the two positive roots. For m=n=2m=n=2, n=q=2n=q=2 and m=q=2m=q=2, we give the exhaustive answer to the question which the positions of the two moduli of positive roots can be.

Keywords

Cite

@article{arxiv.2404.13943,
  title  = {On a problem inspired by Descartes' rule of signs},
  author = {Vladimir Petrov Kostov},
  journal= {arXiv preprint arXiv:2404.13943},
  year   = {2024}
}