Resumo

MARTIN, P.; OLIVARES, J.  e  SOTOMAYOR, A.. Precise analytic approximation for the modified Bessel function I ₁ (x). Rev. mex. fis. [online]. 2017, vol.63, n.2, pp.130-133. ISSN 0035-001X.

Precise analytic approximations have been found for the modified Bessel function I 1 (x) of order one. The approximant is simple and with good accuracy for every positive value of the variable x. The method to obtain the approximant is an improvement of the multipoint quasi-rational approximation technique, MPQA. This is obtained combining rational functions with elementary auxiliary functions as a bridge function between the power series and asymptotic expansion.

Palavras-chave : Approximations and expansions; special functions.