2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/129754We discuss the possibility to represent smooth nonnegative matrix-valued functions as finite linear combinations of fixed matrices with positive real-valued coefficients whose square roots are Lipschitz continuous. This issue is reduced to a similar problem for smooth functions with values in a polyhedron.19 pagesOptimization and ControlAnalysis of PDEs15A99, 65M06text