On the existence of positive solutions for a class of singular boundary value problems ✩

In this paper, by the use of a fixed point theorem, many new necessary and sufficient conditions for the existence of positive solutions in C[0, 1]∩C1[0, 1]∩C2(0, 1) or C[0, 1]∩C2(0, 1) are presented for singular superlinear and sublinear second-order boundary value problems. Singularities at t = 0, t = 1 will be discussed.  2004 Elsevier Inc. All rights reserved.