Electronic Journal of Differential Equations,
Vol. 2009(2009), No. 115, pp. 1-11.

Title: Upper and lower solutions for a second-order three-point
       singular boundary-value problem

Authors: Qiumei Zhang (Changchun Univ., China)
         Daqing Jiang (Northeast Normal  Univ., Changchun, China)
	 Shiyou Weng  (Changchun Univ., China)
	 Haiyin Gao   (Changchun Univ., China)

Abstract: 
  We study the singular boundary-value problem
 $$\displaylines{
 u''+ q(t)g(t,u)=0,\quad  t \in (0,1),\; \eta  \in (0,1),\;\gamma >0\cr
 u(0)=0,  \quad   u(1)=\gamma u(\eta)\,.
 }$$
 The singularity may appear at $ t=0$ and the function $g$ may
 be superlinear at infinity and may change sign.
 The existence of solutions is obtained via an upper and lower
 solutions method. 

Submitted January 27, 2009. Published September 12, 2009.
Math Subject Classifications: 34B15, 34B16.
Key Words: Singular boundary-value problem;  upper and lower solutions; 
           existence of solutions; superlinear.