Mathematics in Ancient and Medieval India c8.2

c8.2

The work of Hipparchus ( c. 150 B. C. ), Menelaus of Alexandria ( c. 100 A. D. ) and Ptolemy ( c. 150 A. D. ) in connection with astronomical problems in the early Christian Era led to the growth of trigonometrical knowledge in Greece in a rather fragmentary character. It was however at a later date ( 4th to 12th century A.D. ) the Indian developed the subject in a systematic manner almost resembling its modern form. This was then transmitted to the Arabs by the beginning of 9th century A.D., who introduced some further improvement. From the Arabs, the knowledge went to Europe where a detailed account of trigonometrical knowledge first appeared in the work *De Triangulis* of Regiomontanus ( 1533 A.D. ).