Thomas Fincke

Thomas Fincke (1561 to 1656) was a Danish mathematician and physicist who held a chair at the University of Copenhagen for more than sixty years. Born Thomas Jacobsen Fincke in Flensburg in Schleswig, the son of a town councillor, he studied mathematics, rhetoric and philosophy for five years at the University of Strasbourg from 1577. His lasting achievement is the book Geometria rotundi of 1583, in which he introduced the modern names tangent and secant for two of the trigonometric functions. In 1590 he became professor of mathematics at Copenhagen, and in 1603 he took a second professorship, in medicine. He married Ivaria Jungesdatter Ivers, and his daughters married the anatomist Caspar Bartholin the Elder, the botanist Jorgen Fuiren, the polymath Ole Worm and the theologian Hans Brochmand, so that much of Copenhagen's seventeenth century learned circle was his family. His son Jacob Fincke became a professor of physics. He died in Copenhagen and was buried at Vor Frue Kirke.