2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/71372In this paper we consider the following two-phase obstacle-problem-like equation in the unit half-ball $Δu = λ_{+}χ_{\{u>0\}}-λ_{-}χ_{\{u<0\}}, λ_\pm>0$. We prove that the free boundary touches the fixed one in (uniformly) tangential fashion if the boundary data $f$ and its first and second derivatives vanish at the touch-point.14 pages, 3 figuresAnalysis of PDEs35R35text