Positive solutions for boundary value problems of functional differential equations

We study the existence of positive solutions of the second order boundary values problems of functional differential equations x '' (t) + f(t, x(t)) = 0, 0 < t < T, x(0) = phi, x(T) = A, where f : [0, T] x C-r --> R is a continuous function, phi is an element of C-r(:= C[-r, 0]) and A is an element of R. The proof of our main result is based upon the fixed point theorem in cones. (C) 2007 Published by Elsevier Inc.