The Existence Of Positive Solution Involving Third Order Differential Equation Boundary Value Problem Is Discussed

In this paper, the second-and third-order ordinary differential equations Strum-Liou-ville boundary value conditions, study of third-order ordinary differential equations ofnonlinear boundary value problem, the main contents are as follows:The first chapter introduces the background and significance of this study, and givessome basic definitions and lemmas used later.The second chapter use the Banach contraction mapping principle to investigate aclass of third order point nonlinear ordinary differential equations meet the conditions, ofStrum-Liouville boundary value of the boundary value problem, existence and uniquene-ss theorem the boundary value.The third chapter use Krasnosellkii fixed point theorem, the index of fixed pointtheorem and monotone iterative method to study the nonlinear terms of third-orderordinary differential equations with singular a (t)function, To meet the existence ofsolutions under certain conditions, at least one or two of the singular boundary valueproblems existence of positive polutions of the conditions.