"Elements of the Theory of Functions of Complex Variable and Operational Calculus" by B. F. Chaplygina is an important work that immerses the reader in the world of complex mathematical concepts, representing not only a textbook, but also a source of inspiration for students, graduate students and anyone interested in mathematics and its applications in various fields of science and technology. In this edition, the authors seek to explain the basic principles and methods of the theory of functions of a complex variable, as well as operational calculus, which allows the reader not only to learn basic knowledge, but also to delve into more complex aspects of these disciplines. Chaplygin, known for his deep knowledge and ability to explain complex ideas, creates a unique atmosphere in which even the most confusing topics become understandable and interesting. The book covers a wide range of issues, ranging from the basics of complex analysis to the application of operational calculus in various tasks. The reader will be able to learn about such key concepts as analytical functions, integration contours, Cauchy's theorem and many others. These topics are not only important for theorists, but also find practical application in physics, engineering, and other sciences, making the book particularly valuable for engineering students. This work will be useful for both undergraduate students of mathematical and physical faculties, and for graduate students engaged in research activities. If you are looking for a textbook that will help you not only prepare for exams, but also expand your horizons in mathematics, then "Elements of the theory of functions of complex variable and operational calculus" will be an excellent choice. The topics raised in the book are relevant and in demand in the modern world, where mathematics plays a key role in scientific research and technological developments. Chaplygin focuses on how theoretical knowledge can be applied in practice, which makes his work especially valuable for those who seek not only theoretical, but also practical understanding of mathematics. The style of the author is distinguished by clarity and logical presentation, which allows the reader to easily follow the course of thought and absorb the material. Chaplygin, as an experienced teacher and researcher, uses many examples and tasks that help to consolidate what he has learned. His approach to learning makes the book not only useful, but also fascinating, which is rare in educational literature. If you are looking for literature that will help you to better understand the theory of complex variable functions and operational calculus, look for "Elements of the theory of complex variable and operational calculus functions". This book will be your reliable companion in the world of mathematics and will help you open new horizons in the study of this fascinating science. In the end, work B. F. Chaplygina is not just a textbook, but a real find for anyone who wants to deepen their knowledge in mathematics and apply them in real life. Do not miss the opportunity to get acquainted with this outstanding work that will inspire you to new discoveries and achievements in your educational and professional activities.