Variational and Quasivariational Inequalities . An Appendix to Free Frontier Tasks by Claudio Bayocchi, Antonio Capelo and B. and . Agoshkova is a unique work that combines the theoretical foundations and practical aspects of variational methods in mathematics and their application in free-boundary problems. This publication will be a real find for students, graduate students and specialists in the field of applied mathematics, mechanics and engineering sciences .. On the pages of the book, the reader plunges into the world of variational and quasivariable inequalities, which play a key role in modern mathematical analysis. The authors propose a deep and systematic study of these concepts, starting with basic definitions and ending with complex applications. The book covers a wide range of topics, including the theory of the existence of solutions, methods of their construction and stability analysis. Particular attention is paid to problems with free borders, which makes the work especially relevant for those who work in the field of mathematical modeling and numerical methods. Who can like this edition? First of all, it will be interesting for senior students and graduate students studying mathematical analysis, functional analysis and applied mathematics . The book will also be useful to researchers and practitioners working in the field of mechanics, physics and engineering, where variational methods are widely used. If you are passionate about mathematical modeling, optimization and finding solutions to complex problems, this publication will become an indispensable assistant for you. The book raises important topics, such as the existence and uniqueness of solutions to variational problems, methods of their numerical solution and application to real-world problems. The authors carefully study each topic, providing the reader with not only theoretical calculations, but also practical examples, which makes the material accessible and understandable. The reader will be able to see how abstract mathematical concepts are applied to solve specific problems, which greatly increases the value of the book. The style of the authors is distinguished by clarity and logical presentation, which makes it easy to assimilate complex ideas. Claudio Bayocchi and Antonio Capelo are known for their work in mathematical analysis and variational methods, and B. and . Agoshkov is a recognized specialist in the field of applied mathematics. Their joint creativity in this book creates a unique synthesis of theory and practice that will be of interest to both beginners and experienced professionals. If you are looking for literature on variational methods, quasivariable inequalities, and their applications, then "Variational and quasivariable inequalities. Application to tasks with a free border" will be an excellent choice for you. This book will not only expand your knowledge, but also inspire new research and discoveries in the field of mathematics. Do not miss the opportunity to get acquainted with this outstanding work, which will be an important step on your way to understanding complex mathematical concepts and their practical application. Read, explore and open new horizons with authors who have contributed to the development of science and education