Introduction to the Theory of Approximation by B. and . Ivanova is a fascinating and deep dive into the world of mathematical analysis, which will become an indispensable tool for both students and professionals seeking to expand their knowledge in the field of numerical methods and approximation theory. In this work, the author not only outlines the theoretical foundations, but also offers the reader practical examples, which makes the material accessible and understandable. The main theme of the book is the study of methods of approximate solution of mathematical problems that arise in various fields of science and technology. In. and . Ivanov masterfully explains how approximations can effectively solve complex equations and optimize computational processes. Readers will be able to learn about different approaches to the approximation of functions, such as polynomial, trigonometric and other methods, as well as how these methods are applied in practice. The book is filled with examples that illustrate the application of the theory to real-world problems, making it especially valuable for those who want to not only understand the theory, but also learn how to apply it. This book will be of interest to a wide range of readers: from undergraduate students of mathematical and engineering specialties to graduate students and practitioners in the field of applied mathematics, physics and computer science. If you are passionate about mathematics and want to deepen your knowledge in the field of numerical methods, the “Introduction to approximation theory” will be a real find for you. The book will also be useful to teachers and researchers who are looking for quality material for the preparation of lectures or scientific articles. The topics raised in the book cover a wide range of issues, such as convergence of methods, estimation of errors and application of approximation theory in various scientific disciplines. In. and . Ivanov emphasizes the importance of accuracy and reliability of calculations, which is critical in today's world, where data and its processing play a key role. The book emphasizes that even small errors in calculations can lead to serious consequences, and offers readers tools to minimize these risks. The author's style is distinguished by clarity and logical presentation, which makes it easy to assimilate even the most complex concepts. In. and . Ivanov is known for his other work in mathematics, and his approach to learning is always focused on the practical application of knowledge. He is able to find a balance between theory and practice, which makes his books in demand among students and professionals. If you are looking for literature that will help you to understand the intricacies of approximation theory, as well as the application of this knowledge to real-world problems, then “Introduction to approximation theory” is what you need. This book will be your reliable assistant in the study of mathematics and will open up new horizons in the understanding of numerical methods. Do not miss the opportunity to immerse yourself in the world of mathematical analysis with B. and . Ivanov and discover the limitless possibilities that the theory of approximations provides!