Coba jelasin Al-Batanni dari Matematik pada zaman pertengahan Islam dalam bahasa melayu dong

Arab mathematician and astronomer Abu Abdallah Muhammad ibn Jabir al-Battani (868-929) made accurate astronomical observations which allowed him to improve on Ptolemy's data for the Sun and the Moon. He also produced a number of trigonometrical relationships:

He also solved the equation sin x = a cos x discovering the formula:

and used al-Marwazi's idea of tangents ("shadows") to develop equations for calculating tangents and cotangents, compiling tables of them.