This book has the objective of teaching the technique of solving certain forms of partial differential equations, initial-boundary value problems of partial differential equations, and certain forms of systems of partial differential equations.

The necessary theory is developed understandably with clarity and without verbosity, while particular emphasis is placed on various methods of solution. Because the subject of partial differential equations is quite extensive, the content of this book is limited to that material which is taught in the Universities and Technical Institutes of the country and which concerns approximately the linear partial differential equations of first or second order for functions of two variables.

It was deemed appropriate not to use a unified notation for the functions (of two variables) or their partial derivatives, or for the forms of Laplace or Fourier transforms, as there is no unified notation in the Greek literature.

The book is divided into six chapters: The first chapter is introductory. The second chapter contains first-order partial differential equations. The third chapter contains partial differential equations of order greater than or equal to two, with constant coefficients. The fourth chapter contains some second-order partial differential equations with variable coefficients. The fifth chapter contains boundary value problems. Finally, the sixth chapter contains systems of first-order partial differential equations.

At the end of each chapter, solved exercises are included, while at the end of the sixth chapter, general solved exercises are also included. The author believes that this book (which is the ninth in the 'Aithra' series - library of advanced mathematics) will serve as an important aid for students of the natural sciences.

Athens, June 1993, Vangelis Spandagos