Skip to main content
37 votes
Accepted

How was Lagrange appointed professor of mathematics so early?

Lagrange enrolled to the university at the age of 14, to study law. But he quickly switched to mathematics. According to his biography, his mother was surprised when the French ambassador presented ...
Alexandre Eremenko's user avatar
12 votes
Accepted

How does Legendre transformation in classical mechanics relate to Adrien-Marie Legendre?

The Legendre transform is not tethered to classical mechanics, it is just one application of it, another one is to thermodynamics. Geometrically, it is a general way to re-represent convex functions ...
Conifold's user avatar
  • 77.1k
8 votes
Accepted

Where did Lagrange prove the Four Squares Theorem?

The proof was submitted to the Berlin Academy in 1770, but published only in 1772. It does not appear in Réflexions, the citation is Lagrange, J.-L.: Démonstration d’un théorème d’arithmétique. ...
Conifold's user avatar
  • 77.1k
6 votes

Book suggestions on Lagrangian and Hamiltonian mechanics?

In my opinion the existing books are not good sources of information. In particular: what is presented as 'historical information' is often incorrect. I believe only the following two categories of ...
Cleonis's user avatar
  • 804
4 votes
Accepted

Where did Lagrange write his technique of resolvents for solving polynomials?

The relevant publication seems to have been published across two annual volumes (for the years 1770 and 1771, but likely printed in 1773) of the Proceedings of the Royal Academy of Science and ...
njuffa's user avatar
  • 6,644
3 votes
Accepted

What are the direct predecessors of Lagrange's theory of quadratic forms?

The motivation for the theory of quadratic forms was representation of integers by sums of squares. This business was started by Fermat and continued by Euler, Lagrange and Legendre, then Gauss. ...
Alexandre Eremenko's user avatar
3 votes
Accepted

Was Lagrange aware of Hamiltonian mechanics?

Yes, he was, at least in a particular example. Near the end of his life, in 1808-09, Lagrange studied perturbative dynamics of a planet on an elliptic orbit, and derived what came to be called ...
Conifold's user avatar
  • 77.1k
3 votes

Does the word "God" appear regularly in the works of Joseph Lagrange?

Contrary to Antommarchi's "The Last Moments of Napoleon", the text Talks of Napoleon at St. Helena quotes Napoleon (bottom of page 274): Napolean replies: How comes it, then, that Laplace was an ...
nwr's user avatar
  • 6,879
2 votes
Accepted

What was Lagrange's contribution to the Knights Tour Problem?

It does not seem like there was much of a contribution, if any Lagrange is sometimes mentioned, without reference, e.g. by Borell, along with Taylor and de Moivre, as one who "worked" on it. ...
Conifold's user avatar
  • 77.1k
1 vote

Does Lagrange's FTA proof meet rigorous requirements even by modern standards?

Yes, Gauss mentions Lagrange too. He wrote “This great mathematician tried above all to fill in the gaps in Euler's first proof, and indeed, as regards what constitutes the second and fourth ...
José Carlos Santos's user avatar
1 vote
Accepted

Does the word "God" appear regularly in the works of Joseph Lagrange?

This is an anecdote, probably invented to complement the other anecdote about Laplace. It is hard to say why Lagrange in particular was picked to fill the part, as he is a bad fit. Probably, it is ...
Conifold's user avatar
  • 77.1k

Only top scored, non community-wiki answers of a minimum length are eligible