"The authors succeeded in adding a very valuable book to the literature available on the history of the calculus of variations. The book is full of the mathematics of the masters and the authors have taken pain to clarify even the details in nowadays mathematical notations." (Thomas Sonar, zbMATH 1350.01001, 2017)

• Preface.- Some Introductory Material.- The Brachystochrone Problem: Johann and Jakob Bernoulli.- Isoperimetrical Problems: Jakob and Johann Bernoulli.- Shortest Lines and Geodesics.- Euler's Memoirs of 1738 and 1741.- Euler's Method us Inveniendi.- Lagrange's δ-Calculus.- Bibliography.- Index of Names.- Subject Index.

"The authors succeeded in adding a very valuable book to the literature available on the history of the calculus of variations. The book is full of the mathematics of the masters and the authors have taken pain to clarify even the details in nowadays mathematical notations." (Thomas Sonar, zbMATH 1350.01001, 2017)

• Preface.- Some Introductory Material.- The Brachystochrone Problem: Johann and Jakob Bernoulli.- Isoperimetrical Problems: Jakob and Johann Bernoulli.- Shortest Lines and Geodesics.- Euler's Memoirs of 1738 and 1741.- Euler's Method us Inveniendi.- Lagrange's δ-Calculus.- Bibliography.- Index of Names.- Subject Index.

"The authors succeeded in adding a very valuable book to the literature available on the history of the calculus of variations. The book is full of the mathematics of the masters and the authors have taken pain to clarify even the details in nowadays mathematical notations." (Thomas Sonar, zbMATH 1350.01001, 2017)

• Preface.- Some Introductory Material.- The Brachystochrone Problem: Johann and Jakob Bernoulli.- Isoperimetrical Problems: Jakob and Johann Bernoulli.- Shortest Lines and Geodesics.- Euler's Memoirs of 1738 and 1741.- Euler's Method us Inveniendi.- Lagrange's δ-Calculus.- Bibliography.- Index of Names.- Subject Index.