Did Euler and Lagrange really come up with the Euler Equation in the calculus of variations. I have seen later work by Weierstrass, Zermeerlo and others that indicates that the Euler- equation was not known by them in its present form! I guess I am wrong but tell me!
All the best
Karl-Gustaf Lofgren
Professor of Economics
Umeå University, Umeå, Sweden.