Talk:Mollweide's formula

Installed a standard triangular drawing for the article's formula to reference.. —Preceding unsigned comment added by 169.230.110.161 (talk • contribs)

Origin of Mollweide's formulas
According to Anton Braunmühl (who did a very careful analysis): ″Vorlesungen ueber Geschichte der Trigonometrie″, Vol 2, Teubner, Leipzig 1900, only the first formula was published by Newton (in his Arithmetica Universalis). Both formulas together were published for the first time 1746 in Friedrich Wilhelm von Oppel's ″Analysis Triangulorum″ (on page 18). ZetaGamma (talk) 14:13, 30 November 2022 (UTC)


 * You will notice I recently added the following: A variant in more geometrical style was first published by Isaac Newton in 1707 and then by Friedrich Wilhelm von Oppel in 1746. Thomas Simpson published the now-standard expression in 1748. Karl Mollweide republished the same result in 1808 without citing those predecessors. citing H. C. Bradley, T. Yamanouti, W. V. Lovitt and R. C. Archibald (1921) "Discussions: Geometric Proofs of the Law of Tangents" The American Mathematical Monthly Vol. 28, No. 11/12, pp. 440-443.
 * Feel free to elaborate further in the article if you want (e.g. by directly describing the geometrical versions of Newton and Von Oppel in the article), or to add the relevant citation(s) from Newton, Von Oppel, Simpson, Mollweide, Braunmühl, or others. –jacobolus (t) 16:05, 30 November 2022 (UTC)