Kuczma M. An Introduction to the Theory of Functional Equations and Inequalities: Cauchy's Equation and Jensen's Inequality

Basel: Birkhäuser, 2008. — 609 p.The first edition of Marek Kuczma’s book An Introduction to the Theory of Functional Equations and Inequalities was published more than 20 years ago. Since then it has been considered as one of the most important monographs on functional equations, inequalities and related topics. As J´anos Acz´el wrote in Mathematical Reviews
. this is a very useful book and a primary reference not only for those working in functional equations, but mainly for those in other fields of mathematics and its applications who look for a result on the Cauchy equation and/or the Jensen inequality.
Based on the considerably high demand for the book, which has even increased after the first edition was sold out several years ago, we have decided to prepare its second edition. It corresponds to the first one and keeps its structure and organization almost everywhere. The few changes which were made are always marked by footnotes.
Several colleagues helped us in the preparation of the second edition. We cordially thank Roman Ger for his advice and help during the whole publication process, Karol Baron and Zolt´an Boros for their conscientious proofreading, and Szabolcs Baj´ak for typing and continuously correcting the manuscript. We are grateful to Eszter Gselmann, Fruzsina M´esz´aros, Gy¨ongyv´er P´eter and P´al Burai for typesetting several chapters, and we would like to thank the publisher, Birkh¨auser, for undertaking and helping with the publication.
The new edition of Marek Kuczma’s book is paying tribute to the memory of the highly respected teacher, the excellent mathematician and one of the most outstanding researchers of functional equations and inequalities.