Copyright © 2009 Minghe Pei and Sung Kag Chang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
We are concerned with the higher-order nonlinear three-point boundary value problems: x(n)=f(t,x,x′,…,x(n−1)),n≥3, with the three point boundary conditions g(x(a),x′(a),…,x(n−1)(a))=0; x(i)(b)=μi,i=0,1,…,n−3;h(x(c),x′(c),…,x(n−1)(c))=0, where a<b<c,f:[a,c]×ℝn→ℝ=(−∞,+∞) is continuous, g,h:ℝn→ℝ are continuous, and μi∈ℝ,i=0,1,…,n−3 are arbitrary given constants. The existence and uniqueness results are obtained by using the method of upper and lower solutions together with Leray-Schauder degree theory. We give two examples to demonstrate our result.