## Taqi al Din Ibn Ma’ruf 's Work on Extracting the Cord 2<sup>o</sup> and Sin 1<sup>o</sup>

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 1^{o} or Cord 2^{o} 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.

Rate this article: