This book ideologically precedes the book of these same atories Elements of Mathematical Physics . It is not a systematic textbook, but rather a book to read. On simple examples taken from physics, on various mathematical problems, the authors tried to introduce the reader to the range of ideas and methods that are now widely used in the applications of mathematics to physics, engineering and some other areas. Some of these ideas and methods (such as the use of delta function, the principle of superposition, asymptotic expressions, etc.) d. ) are still not sufficiently covered in the common mathematical textbooks for non-mathematicians, so that here this book can serve as a supplement to these textbooks. the purpose of the authors was to explain the basic ideas of mathematical methods and the general regularities of the phenomena under consideration . On the contrary, formal evidence, consideration of exceptions and complicating factors are omitted where possible. Instead, in some places, the authors tried to go into more detail in the physical picture of the processes under consideration. ADMINISTRATIONChapter 1. Some Numerical Methods. Chapter II Mathematical Processing of the Results of Experience . Chapter III. More information about integrals and series. Chapter IV. Functions of several variables. Chapter V. Functions of complex variable. Chapter VI. Dirac Delta Function. Chapter VII . Differential Equations . Chapter VIII . Further information on differential equations. Chapter IX. Vectors. Chapter X. Field theory . Chapter XI. Vector work and rotation. Chapter XII . Variational calculus. Chapter XIII. Probability theory . Chapter XIV. Fourier transform. Chapter XV. Electronic digital computers. Other books by author: Mathematical Theory of Combustion and Explosion. Elements of Mathematical Physics . Higher Mathematics for Beginners and its Application to Physics. The Structure and Evolution of the Universe . The Drama of Ideas in the Knowledge of Nature . Physics of shock waves and high-temperature hydrodynamic phenomena. Higher Mathematics for Beginner Physicists and Technicians