2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/86719Evolution of the main signal in a Lorentz dispersive medium is considered. The signal propagating in the medium is excited by a sine-modulated pulse signal, with its envelope described by a hyperbolic tangent function. Both uniform and non-uniform asymptotic representations for the signal are found. It is shown when the uniform representation can be reduced to the non-uniform one. The results obtained are illustrated with a numerical example.12 pages, 4 figuresOpticstext