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

40 The first term on the right hand side is termed as the Adhimāsa-graha, and the second term is evidently 13 times the position of the Sun whereas the term on the left-hand- side is the Moon’s position. Hence, ignoring the integral number of revolutions, we have Moon’s position = Adhi- māsa — graha + 13 times Sun’s position (Ignoring the number of integral revolutions means subtracting integral revolutions or adding them if necessary). Verses 12, 13. A few more examples on the afore- said principle. The planetary position obtained by the sum of the sidereal revolutions of two planets, added to or Subtracted from another planetary position obtained by the difference of the sidereal revolutions of two planets and divided by two gives the positions of the two planets res- pectively, the quicker of the two in the first case and the slower in the second. Similarly the planetary position com- puted from the difference of the sidereal revolutions of two planets subtracted from the planetary position of the quicker of the two gives the position of the slower whereas the former planetary position added to the position of the slower gives the quicker. Comm. We have [(P₁ + P₂) + (P₁ − P₂)] / 2 = P₁ (1) and [(P₁ + P₂) − (P₁ − P₂)] / 2 = P₂ (2) where P₁ is the number of sidereal revolutions of a quick-moving planet and P₂ that of a slow-moving one. Multiplying the above equa- tions by A/M with the former notation, [A/M (P₁ + P₂) + A/M (P₁ − P₂)] / 2 = (P₁ × A) / M (3) and [A/M (P₁ + P₂) − A/M (P₁ − P₂)] / 2 = A/M × P₂ (4) Equations (3) and (4) mean what has been stated in verse (12). Again we have the equations P₁ − (