Letter to d'Alembert (1781) cited in R. Laubenbacher, D. Pengelly: Mathematical Expeditions: Chronicles by the Explorers (1999) Springer, pp. 233–234.
Joseph Louis Lagrange: Geometry
Joseph Louis Lagrange was Italian mathematician and mathematical physicist. Explore interesting quotes on geometry.Dans Les Leçons Élémentaires sur les Mathématiques (1795) Leçon cinquiéme, Tr. McCormack, cited in Moritz, Memorabilia mathematica or, The philomath's quotation-book (1914) Ch. 15 Arithmetic, p. 261. https://archive.org/stream/memorabiliamathe00moriiala#page/260/mode/2up
Dans Les Leçons Élémentaires sur les Mathématiques (1795) Leçon cinquiéme,Tr. McCormack, cited in Robert Edouard Moritz, Memorabilia mathematica or, The philomath's quotation-book (1914) Ch. V The teaching of mathematics, p. 81. https://archive.org/stream/memorabiliamathe00moriiala#page/80/mode/2up