Gabriel Cramer
Gabriel Cramer ( born July 31, 1704 Geneva, † January 4, 1752 in Bagnols -sur -Cèze, France ) was a Genevan mathematician.
Life
Cramer was a doctor's son Jean Isaac Cramer. He had two brothers. In 1722 he received his doctorate in Geneva for his work in the field of acoustics. 1724 he became professor of mathematics at the University of Geneva. Here he suggested that not only the lectures - as was customary - to hold in Latin, but also in French. On several trips from 1727 to 1729 he met with leading mathematicians of his time:
- In Basel with Johann Bernoulli and Leonhard Euler,
- In England with Edmond Halley, Abraham de Moivre, James Stirling and others,
- In Leiden with ' sGravesande,
- Bernard le Bovier in Paris with de Fontenelle, Pierre- Louis Moreau de Maupertuis, Georges -Louis Leclerc de Buffon and Alexis -Claude Clairaut.
This meeting and subsequent correspondence influenced his work.
In 1750, he published the book " Introduction à l' analyze the lignes courbes algébriques ". In one of the appendices, a formula appears for solving linear systems of equations, which is known as Cramer's rule. This is the impetus for the development of the theory of determinants.
He also wrote works on jurisprudence and political philosophy and the history of mathematics. In addition to his work as a professor, he held public office, contributed to military and defense projects of his government, was a consultant with repairs to churches and conducted research in church archives.
Works
- Source est la cause de la figure elliptique of planètes et de la mobilité de leur aphélies? , Geneva 1730. This work he submitted to the Paris Academy. She received the second prize ( the first prize was won by Johann Bernoulli ).
- Introduction à l' analyze the lignes courbes algébriques, Geneva in 1750. Here he examines algebraic curves; appears in Appendix 1, the Cramer's rule named after him, but without proof.
- Publication of the Opera Omnia work of Johann Bernoulli, 1742, 4 volumes.
- Publication of Works of Jakob Bernoulli, 1744, 2 volumes. Included are all the works of Jakob Bernoulli, with the exception of the work Ars conjectandi.
- Publication (together with Johann Castillon ) of the correspondence between Johann Bernoulli and Leibniz, 1745