Positive Solutions to a Class of Elliptic Boundary Value Problems

We prove the existence of positive solutions to the boundary value problems Duqla x.f u.s0 inV, us0 on­V, where V is a bounded domain in RN, a: VªR may change sign, f 0.)0, and l )0 is sufficiently small. Our approach is based on the Leray]Schauder fixed point theorem.