Calculus Of Variations | I.M. Gelfand, S.V. Fomin

This book is a modern introduction to the calculus of variations and certain of its ramifications, and I trust that its fresh and lively point of view will serve to make it a welcome addition to the English-language literature on the subject. The present edition is rather different from the Russian original. With the authors’ consent, I have given free rein to the tendency of any mathematically educated translator to assume the functions of annotator and stylist. 

The problems appearing at the end of each of the eight chapters and two appendices were made specifically for the English edition, and many of them comment further on the corresponding parts of the text.