ORDINARY DIFFERENTIAL EQUATIONS develops the theory of initial-, boundary-, and eigenvalue problems, real and complex linear systems, asymptotic behavior and stability. Using novel approaches to many subjects, the book emphasizes differential inequalities and treats more advanced topics such as Caratheodory theory, nonlinear boundary value problems and radially symmetric elliptic problems. Applications from mechanics, physics, and biology are included, and exercises, which range from routine to demanding, are dispersed throughout the text.