Nonlinear Singular BVP of Limit Circle Type and the Presence of Reverse-Ordered Upper and Lower Solutions

الملخص EN

We consider the following class of nonlinear singular differential equation -(p(x)y'(x))'+q(x)f(x,y(x),p(x)y'(x))=0, 0

Conditions on p(x) and q(x) ensure that x=0 is a singular point of limit circle type.

A simple approximation scheme which is iterative in nature is considered.

The initial iterates are upper and lower solutions which can be ordered in one way (v0≤u0) or the other (u0≤v0).