By: FSTC Limited, Fri 30 May, 2008 This article by Professor Sevim Tekeli, a leading historian of science in the Ottoman period, deals with an aspect of the work of Taqi al-Din Ibn Ma'ruf in trigonometry, a mathematical discipline which studies the relationships between the sides and the angles of triangles and the trigonometric functions which describe those relationships. Approaching Taqi al-Din's work through modern methods of notation, his mathematical method in extracting the cord 2o and Sin 1o is fully disclosed. The author shows the originality of Ibn Ma'ruf's discovery and states how it constituted a progress with regard to his predecessors, in Greek and Islamic mathematics.
