Applied Calculus of Variations for Engineers, Third edition

Calculus of variations has a long history. Its fundamentals were laid down by icons of mathematics like Euler and Lagrange. It was once heralded as the panacea for all engineering optimization problems by suggesting that all
one needed to do was to state a variational problem, apply the appropriate Euler-Lagrange equation and solve the resulting differential equation.

This, as most all encompassing ...