Ordinary differential equations have long been an important area of study because of their wide application in physics, engineering, biology, chemistry, ecology, and economics. Based on a series of lectures given at the Universities of Melbourne and New South Wales in Australia, Nonlinear Ordinary Differential Equations takes the reader from basic elementary notions to the point where the exciting and fascinating developments in the theory of nonlinear differential equations can be understood and appreciated. Each chapter is self-contained, and includes a selection of problems together with some detailed workings within the main text. Nonlinear Ordinary Differential Equations helps develop an understanding of the subtle and sometimes unexpected properties of nonlinear systems and simultaneously introduces practical analytical techniques to analyze nonlinear phenomena. This excellent book gives a structured, systematic, and rigorous development of the basic theory from elementary concepts to a point where readers can utilize ideas in nonlinear differential equations.INTRODUCTION Preliminary Notions First-Order Systems Uniqueness and Existence Theorems Dependence on Parameters, and Continuation LINEAR EQUATIONS Uniqueness and Existence Theorem for a Linear System Homogeneous Linear Systems Inhomogeneous Linear Systems Second-Order Linear Equations Linear Equations with Constant Coefficients LINEAR EQUATIONS WITH PERIODIC COEFFICIENTS Floquet Theory Parametric Resonance Perturbation Methods for the Mathieu Equation The Mathieu Equation with Damping STABILITY Preliminary Definitions Stability for Linear Systems Principle of Linearized Stability Stability for Autonomous Systems Liapunov Functions PLANE AUTONOMOUS SYSTEMS Critical Points Linear Plane, Autonomous Systems Nonlinear Perturbations of Plane, Autonomous Sysl#¼