Jyā, koti-jyā and utkrama-jyā

Jyā, koti-jyā, and utkrama-jyā are terms from classical Indian mathematics and astronomy, particularly in the context of trigonometry and spherical geometry. 1. **Jyā (ज्या)**: This term refers to what we would call the sine function in modern trigonometry. In classical Indian texts, "jyā" was used to describe the half-chord of an arc in a circle.