Abstract
This article is of the nature of a survey. It sets out the basic steps of the investigations into the exact solution of extremal problems in the theory of approximation for classes of periodic functions in their historical aspect (best approximation by trigonometric polynomials, diameters, approximation of one class of functions by another, etc.) Special attention is given to explaining the principles characterizing the various approaches to the solution of the problems. A method worked out by the author and connected with the application of a special operator that is defined by means of rearrangements is expounded in greater detail. This method enables us to obtain an exact solution of certain extremal problems for the classes .
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
