Who are the mathematicians that developed trigonometry?

Answer 1

The first recorded use of trigonometry came from the Hellenistic mathematician Hipparchus circa 150 BC, who compiled a trigonometric table using the sine for solving triangles. Ptolemy further developed trigonometric calculations circa 100 AD

Development of trigonometry is not the work of any one man or nation. It first originated in India and the basic concepts of angle and measurements was noted in Vedic texts such as Srimad Bhagavatam. However, trigonometry in its present form was established in Surya Siddhanta and later by Aryabhata [5th century CE]. It should be noted that from the time of Hipparchus until modern times there was no such thing as a trigonometric ratio. Instead, the Indian civilization and after them the Greeks and the Muslims used trigonometric lines.

Pythagoras of Samos (580? BC- 500? BC) was an Ionian Greek mathematician and also founder of the religious movement called Pythagoreanism.

Nasir al-Din al-Tusi (1135-1213) (aka Sharafeddin Tusi) widely promulgated studies in trigonometry, which was compiled by him as a new subject in its own right for the first time. He also developed the subject of spherical trigonometry.