Georg Simon Klügel

Georg Simon Klügel (19 August 1739 to 4 August 1812) was a German mathematician and physicist, born in Hamburg, who in 1760 went to the University of Göttingen, where he began with theology before switching to mathematics. His 1763 doctoral thesis, written with Abraham Gotthelf Kästner as doctoral advisor, was a study of thirty attempted proofs of the parallel postulate that was influential and much cited at the time. After editing the Hannöversche Magazin for two years from 1766 he became professor of mathematics at Helmstedt, and in 1788 he succeeded Wenzeslaus Johann Gustav Karsten to the chair of mathematics and physics at Halle, where he died. He made an exceptional contribution to trigonometry, unifying formulae and introducing the concept of the trigonometric function, including coining the term, in his Analytische Trigonometrie of 1770.