2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106399Simple proofs of the Hermite-Biehler and Routh-Hurwitz theorems are presented. The total nonnegativity of the Hurwitz matrix of a stable real polynomial follows as an immediate corollary.4 pagesClassical Analysis and ODEsRings and Algebras93D05, 12D10, 26C05, 26C10, 30C15, 15A23, 15A48, 15A57text