Thomas Fincke (6 January 1561 – 24 April 1656) was a Danish mathematician and physicist, and a professor at the University of Copenhagen for more than 60 years. Biography Thomas Jacobsen Fincke was born in Flensburg in Schleswig. Fincke was the son of Councillor Jacob Fincke and Anna Thorsmede. He completed his primary schooling at Flensburg. From 1577, he studied mathematics, rhetoric and other philosophical studies for five years at the University of Strasbourg. Fincke's lasting achievement is found in his book Geometria rotundi (1583), in which he introduced the modern names of the trigonometric functions tangent and secant. In 1590, he became professor of mathematics at the University of Copenhagen. In 1603 he also obtained a professorship in medicine. Personal life He was married to Ivaria Jungesdatter Ivers (1574-1614). His son Jacob Fincke (1592-1663) was a professor of physics. His daughters married scientist Caspar Bartholin the Elder (1585–1629), botanist Jørgen Fuiren (1581-1628), historian Ole Worm (1588-1654) and theologian Hans Brochmand (1594-1630). Fincke died at Copenhagen and was buried at Vor Frue Kirke. References External links 1561 births 1656 deaths 16th-century Danish scientists 17th-century Danish scientists 16th-century Danish mathematicians 17th-century Danish mathematicians Danish mathematicians Danish physicists Science teachers Mathematics writers University of Strasbourg alumni Academic staff of the University of Copenhagen Rectors of the University of Copenhagen People from Flensburg Burials at the Church of Our Lady, Copenhagen