Ordinary Differential Equations: Brief RevisionFirst-Order Equations Homogeneous Linear Equations with Constant Coefficients Nonhomogeneous Linear Equations with Constant Coefficients Cauchy-Euler Equations Functions and OperatorsFourier SeriesThe Full Fourier Series Fourier Sine Series Fourier Cosine Series Convergence and Differentiation Sturm-Liouville ProblemsRegular Sturm-Liouville Problems Other ProblemsBessel Functions Legendre Polynomials Spherical HarmonicsSome Fundamental Equations of Mathematical PhysicsThe Heat Equation The Laplace Equation The Wave EquationOther EquationsThe Meth.Abstract: Ordinary Differential Equations: Brief RevisionFirst-Order Equations Homogeneous Linear Equations with Constant Coefficients Nonhomogeneous Linear Equations with Constant Coefficients Cauchy-Euler Equations Functions and OperatorsFourier SeriesThe Full Fourier Series Fourier Sine Series Fourier Cosine Series Convergence and Differentiation Sturm-Liouville ProblemsRegular Sturm-Liouville Problems Other Problems Bessel Functions Legendre Polynomials Spherical HarmonicsSome Fundamental Equations of Mathematical PhysicsThe Heat Equation The Laplace Equation The Wave EquationOther EquationsThe Meth