This note concerns the existence of positive solutions for the boundary problems
where and are, respectively, linear and quasilinear uniformly elliptic operators in divergence form in a non-smooth bounded open subset Ω of Rn, 1<p<n, p∗=np/(n−p) is the critical Sobolev exponent and λ is a real parameter. Both problems have been quite studied when the ellipticity of LA and La,p concentrate in the interior of Ω. We here focus on the borderline case, namely we assume that the determinant of A(x) has a global minimum point 2a30fd6ed3dcd804baf016f1fb" title="Click to view the MathML source">x0 on the boundary of Ω such that A(x)−A(x0) is locally comparable to |x−x0|γIn in the bilinear forms sense, where In denotes the identity matrix of order n. Similarly, we assume that a352b04a2dac2fcf970e359433c42" title="Click to view the MathML source">a(x) has a global minimum point 2a30fd6ed3dcd804baf016f1fb" title="Click to view the MathML source">x0 on the boundary of Ω such that a(x)−a(x0) is locally comparable to |x−x0|σ. We provide a linking between the exponents γ and σ and the order of singularity of the boundary of Ω at 2a30fd6ed3dcd804baf016f1fb" title="Click to view the MathML source">x0 so that these problems admit at least one positive solution for any 32a7d6a0fa1b3" title="Click to view the MathML source">λ∈(0,λ1(−LA)) and λ∈(0,λ1(−La,p)), respectively, where 2a3b638c8b16634b" title="Click to view the MathML source">λ1 denotes the first Dirichlet eigenvalue of the corresponding operator.