Basic Theory of Differential Equations and Wronskian; Qualitative Properties of Solution and Oscillation Theory; Power Series Solution of Differential Equations; The Gamma Function; The Hypergeometric Function; Hermite Polynomials; Partial Differential Equations of the First Order; Non-linear Partial Differential Equations of the First Order; Partial Differential Equations of Second Order; Wave, Laplace and Diffusion Equations; Reduction of second order Partial Differential Equation into its canonical (or Normal) Form; Non-Linear Partial Differential Equations of Second Order .