2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60676We give necessary and sufficient conditions for differentiating under the integral sign an integral that depends on a parameter. The conditions require the equality of two iterated integrals and depend on being able to integrate every derivative. The Henstock integral is thus used in an essential way.Classical Analysis and ODEs26A39text