But what happens when the problem changes from finding the point where something is optimized to finding the of a curve that minimizes a quantity? This is the domain of the Calculus of Variations—a field that has given us the brachistochrone problem, the geodesic, and the principle of least action.
If you can find a PDF copy (legally) or purchase the Dover reprint, you will discover a masterful guide to one of mathematics’ most beautiful subjects: the search for the optimal curve. introduction to the calculus of variations hans sagan pdf
In the world of mathematics, most introductory calculus courses focus on a single question: Given a function, where are its maximum and minimum points? But what happens when the problem changes from