Topics: Differential Equations, Modeling, Qualitative Methods, First-Order Differential Equations, Separable First-Order Differential Equations, Exact First-Order Differential Equations, Linear First-Order Differential Equations, Linear Differential Equations, Second-Order Linear Homogeneous Differential, nth-Order Linear Homogeneous Differential Equations, Method of Undetermined Coefficients, Variation of Parameters, Initial-Value Problems, Laplace Transform, matricies, Inverse Laplace Transforms, Convolutions, Unit Step Function, power series, Series Solutions, Classical Differential Equations, Gamma Functions, Bessel Functions, Partial Differentiall Equations, Second-Order Boundary-Value Problems, Eigenfunction Expansions, Difference Equations