# Jacques Ozanam

Jacques Ozanam (* June 16, 1640 in Sainte- Olive (now in the Department of Ain ), † April 3, 1718 in Paris) was a French mathematician.

Ozanam came from a wealthy, converted long before he was born Jewish family. From the same family is the better known Frédéric Ozanam. He studied theology at the Father's desire, however, was more attracted by mathematics, which he mastered through self-study. At the age of 15, he published his first mathematical work. After the death of his father he gave up his studies in theology and began to give in Lyon free private math lessons. Later, when the family estates were given to his older brother, he was forced to charge for these lessons, especially since he lost a lot of money as a passionate player.

In 1670 he published trigonometric and logarithmic number boards that were more accurate than the then existing Adriaan Vlacq ( 1628, also written Ulacq ), Bartholomew Pitiscus and Henry Briggs. Since he was so generous to lend money with no real collateral to two unfamiliar men traveling through, Mr. d' Aguesseau (the father of the French Chancellor ) was aware of him, who invited him to Paris. There he married, had a large family of twelve children ( which, however, usually died early) and lived well off to teach mathematics for private students, mostly foreigners.

Ozanam published numerous books, many of which are sold well and several times were launched, especially Récréations Mathématiques et physiques, which was translated into English later. With this work, recreational mathematics, he contributed to the spread of mathematics. Les six livres de l' Arithmétique de Diophante augmentés Reduits et à la spécieuse was praised by Leibniz. In 1701 he was elected as a member of the Académie des Sciences. His wife's death plunged him into deep mourning, and by the loss of his private students because of the Spanish Succession War, he became impoverished. He died in Paris on 3 April 1718 ( often in 1717, but that is a mistake in dating ).

Ozanam was more honored than at home and abroad. He was a believer and helpful.

## Writings

- Table of sines, tangents, et sécantes (1670 )
- Method générale pour tracer of cadrans ( 1673 )
- Geometry pratique ( 1684)
- Traité des lignes du premier genre ( 1687 )
- De l' usage du compas (1688 )
- Dictionnaire mathématique ( 1691)
- Cours de Mathématiques (Paris 1693, 5 volumes; engl Übers. London 1712)
- Traité de la fortification "(Paris 1694 )
- Récréations Mathématiques et physiques ( 1694, 2 volumes, rev. Montucla of 1778, 4 volumes)
- Nouvelle Trigonometry ( 1698 )
- Méthode facile pour arpenter (1699 )
- Nouveaux Éléments d' Algèbre ( 1702)
- La Géographie et Cosmographie (1711 )
- La Perspective (1711 )