Vol. 11 (2005)
Articles

An elementary evaluation of a quartic integral

George Boros
Department of Mathematics, Tulane University, New Orleans LA, USA
Victor H. Moll
Department of Mathematics, Tulane University, New Orleans LA, USA
Sarah Riley
Department of Mathematics, Tulane University, New Orleans, LA, USA.

Published 23-01-2025

Keywords

  • integrals,
  • rational functions

Abstract

We provide an elementary evaluation for the integral

\[N_{0.4}(a; m) = \int_{0}^{\infty} \frac{dx}{(x^4 + 2ax^2 + 1)^{m+1}}\]

where \(m \in \mathbb{N}  and  a \in (-1, \infty)\)

\[N_{0.4}(a; m) = \frac{2^{m+3/2}}{(a+1)^{m+1/2}}\pi P_m(a)\]

\({for } P_m(a) \text{ a polynomial in } a.\)