सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

before which the Yogas will occur or would have occured. Compute the declinations of the Sun and the Moon for that moment from the then true daily motions. Comm. From fig. 124, it is clear that triangle ♈SL and ♎ MN are congruent so that ♈S = ♎ M ∴ SS₁ = MS₁ ∴ ♈S + ♈M = ♎ M + ♈M = 180°. Again triangle ♈SL and ♈M'N' are congruent ∴ ♈S = M'♈ ∴ ♈S + ♈M' = ♈M' + M'♈ = 360°. Thus in the former case which constitutes Vyatīpāta, the sum of the tropical longitudes of the Sun and the Moon is 180°; whereas in the latter case, which constitutes the Vaidhṛtipāta, the sum of those two longitudes is equal to 360°. Hence we are asked to note when the sum of the two longitudes is likely to amount to 180° or 360°. On a particular day suppose the sum is 180 — θ or 360 — θ; so that θ is to be made up by the then velocities of the Sun and the Moon conjointly. Then θ / (u + v) where u, v are their respective velocities gives the number of days or fractiou of a day, by which the sum would be 180° or 360° as the case may be. As the velocities change from moment to moment, the above θ / (u + v) is only approximate. So, compute again the respective positions and respective velocities. Suppose the sum of the longitudes is 180 ± θ' or 360 ± θ' and the velocities u' and v', Then θ' / (u' + v') gives the fraction of a day after or before the moment in question when the pātas occur Vyatīpāta or Vaidhṛti. Verse 10. To know whether the Yoga is past or future. If the declination of the Moon situated in an odd quadrant exceeds that of the Sun or falls short of the