2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/57825Some difficulties are pointed out in the methods for identification of obstacles based on the numerical verification of the inclusion of a function in the range of an operator. Numerical examples are given to illustrate theoretical conclusions. Alternative methods of identification of obstacles are mentioned: the Support Function Method (SFM) and the Modified Rayleigh Conjecture (MRC) method.9 pages, 2 figuresMathematical PhysicsPrimary 78A46, 65N21, Secondary 35R30text