关键词: boundary , value , problem, positive , soulution, fixed , point, existence

Abstract: This paper deals with the existence of positive solutions of the equation u"+f(t, u)=0 with linear boundary conditions. We show the existence of at least one positive solution if / is neither superlinear nor sublinear on u by a simple application of a fixed point Theorem in cones.

Key words: boundary , value , problem, positive , soulution, fixed , point, existence