सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)
Siddhanta Shiromani Ganitadhyaya of Bhaskaracharya with Commentary
भास्कराचार्य द्वितीय द्वारा
पृष्ठ 185, कुल 573 में से
संदर्भ में पढ़ेंM₂ + E₂ = S I where M₂ = Mandasphuta- graha and E₂ = the Sīghraphala where from we have δM₂ + δE₂ = δS II i.e. Mandasphutagati + Sīghragati phala = Spastagati (a) Let E₂ be maximum so that δE₂ = 0, then δM₂ = δS. This means that in the helio- centric figures 11 and 12, at the points a and b,: the Sīghraphala being maximum, the Mandasphuta gati will be itself the Spashtagati. This line ab, it will be seen corres- ponds with the so called “कक्षामध्यगततिर्यग्रेखा (प्रतिवृत्तसम्पातरेखा)” i.e. the line cutting the eccentric, drawn through the centre of the deferent. (b) The planet begins to retrograde only after the Spashtagati vanishes i.e. after δM₂ + δE₂ becomes Zero. Taking δM₂ to be almost a constant since the Mand