1. Elliptic problems.- 1.1 The Dirichlet problem for the Laplace equation in an annulus.- 1.2 Examples of Dirichlet problems in an annulus.- 1.3 The interior and exterior Dirichlet problems.- 1.4 The Poisson integral for the disc. Complex form. Solution of the Dirichlet problem when the boundary condition is a rational function R(sin ?, cos ?).- 1.5 The interior and exterior Dirichlet problems.- 1.6 Boundary value problems for the Poisson equation in a disc and in an annulus.- 1.7 Boundary value problems for the Laplace and Poisson equations in a rectangle.- 1.8 Boundary value problems for the Laplace and Poisson equations in a bounded cylinder.- 1.9 Boundary value problems for the Laplace and Poisson equations in a ball.- 1.10 Boundary value problems for the Helmholtz equations.- 1.11 Boundary value problem for the Helmoltz equation in a cylinder.- 1.12 Boundary value problems for the Helmoltz equation in a disc.- 1.13 Boundary value problems for the Helmoltz equation in a ball.- 1.14 Guided electromagnetic waves.- 1.15 The method of conformal mappings (for the solution of boundary value problems in the plane).- 1.16 The Green function method.- 1.17 Other methods.- 1.18 Problems for independent study.- 1.19 Answers.- 2. Hyperbolic problems.- 2.1 The travelling-wave method.- 2.2 The method of selection of particular solutions.- 2.3 The Fourier integral transform method.- 2.4 The Laplace integral transform met hod.- 2.5 The Hankel integral transform method.- 2.6 The method of standing waves. Oscillations of a bounded string.- 2.7 Some examples of mixed problems for the equation of oscillations of a string.- 2.8 The Fourier method. Oscillations of a rectangular membrane.- 2.9 The Fourier method. Oscillations of a circular membrane.- 2.10 The Fourier method. Oscillations of a beam.- 2.11 The perturbation method.- 2.12 Problems for independent study.- 2.13 Answers.- Chaper 3. Parabolic problems.- 3.1 The Fourier integral transform method.- 3.2 The Lapalce integral transform method.- 3.3 The Fourier method (method of separation of variables).- 3.4 A modification of the method of separation of variables for solving the Cauchy problem.- 3.5 Problems for independent study.- 3.6 Answers.- References.