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

166 negative when the planet courses the arc of the smaller segment ab, because E₂ decreases from a maximum value to zero. As a matter of fact δE₂ negatively increases along ac and again increases from a negative minum at c to Zero at b as we course along cb (vide fig. 11 & 12). Thus the planet will assume zero velocity at two points symmetrical about c and in between ab. In other words the planet will be retrograde along the arc d₁ cd₂ not entirely along ab as some have misconstrued. Regarding E₂, it is clear that it is zero at S'. then gradually increases to a maximum as the planet traces S'a, the maximum being assumed at a, then it decreases from the maximum to zero as the planet courses the arc ac. and then increases from zero to a maxi- mum at b and finally decreases from that maximum to zero at S' again. Keeping the Earth constant it will be noted that an Inferior planet always goes anticlockwise whereas a Superior planet always goes clockwise. Also it will be seen that the Sīghraphala is positive as the planet courses the arc Sac, whereas it is negative as it courses cbS'. (c) The values of the spashtagati at S' and C will be respectively putting H cos E = R in the formula. Spashtagati = Sīghragati — (H cos Eδm) / K . Here for Sīghragati we may put U and U — V for δm, and putting K = R + r at S' and R — r at C, the values of the spash- tagati would be [U — R (U — V)] / (R + r) and [U — R (U — V)] / (R — r) ie. (RV + ru) / (R + r), (RV — rU) / (R — r) respectively. (RV + rU) / (R + r) > (RV — rU) / (R — r) if R²V — rRV + RrU — r²U > R²V — RrU + rRV — r²U