Mathematics in Ancient and Medieval India c9.54

c9.54

In the Fig. 29 let EQ = Equator, P its pole CT = Ecliptic, K its pole and N = any point on EQ. ν = the first point of aries. It is required to find the complement of the angle vNS In Bhāskara II's terminology, the 'sine' of the required angle is *ayana-valana*. If any point (say S of the ecliptic has a celestial longitude l and δ be its corresponding declination, we have, (Sin δ)/(Sin ω) = (Sin l)/(Sin 90⁰)i.e. Sin δ = Sin l. Sin ω ... (1)