vss. 9- 10 ] Jivabhukti of the sun 21 (thus obtained) by its (tabulated) epicycle and dividing by 80, subtract that from the Sun's mean daily motion if the (Sun's) anomaly is in the half-orbit commencing with Capricorn and add that to the same if (the Sun's anomaly is) in the half-orbit com- mencing with Cancer. (The sum or difference thus obtained) is known as the (Sun's) true daily motion. 1 Let M and M' be the mean longitudes and S and S' the true longitudes of the Sun at sunrise yesterday and today respectively. Also let Q and 0' be the corresponding values of the bhuja (due to the Sun's mean anomaly). Then, we have where r t is the Sun's tabulated epicycle, — or -f- sign being taken according as the Sun's mean anomaly is less than or greater than 180°. Therefore S'-S= (AT- J*} T (Rsi " . . 80 (Rsin Rsin $) x r, = m f 80 where m denotes the Sun's mean daily motion, •— or 4- signs being taken according as the Sun is in the first and fourth or in the second and third anomalistic quadrants. Neglecting the motion of the Sun's apogee and assuming that the Rsines vary uniformly, we have Rsin &' - Rsin = (current R sine-di fference) X m Therefore C c « -r (current Rsine-difference) X m X r t Hence the above rule.. Since the Sun's true daily motion has been obtained here with the help of Rsines ( jha ), therefore it is generally called jhabhukti. 1 Cf. MBh, iv. 14.
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