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

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phala from the extremity of the Karna to the extremity of
the radius in the deferent; but as this Karnānupāta is not
adopted, the difference being negligible the quadrants are
all of equal magnitude i.e. each of 90°.
In the course of the commentary of this verse Bhāskara
mentions that for Mercury, as the maximum S'īghraphala is
21°-31'-43", the quadrants are of magnitude 3-21-31-43,
2-8-28-17, 2-8-28-17 and 3-21-31-43 respectively.
Also in the commentary Bhāskara adds that a₁ which
is the point of intersectiou of the eccentric with the hori-
zontal diameter E₁b₁ the S'īghraphala is maximum and
that at that point the mean motion is itself the true motion
“कक्षामध्यगतिर्यम्रेखाप्रतिवृत्तसम्पाते, मध्यैव गतिः स्पष्टा परं फल तत्र
खेटस्य”. That the S'īghraphala at a₁ and a₃ is maximum is
clear from the figure 13, where it is equal to the arcs b₁c₁ and
b₂c₂ whose H sine is equal to r. To prove that the mean
motion is itself the true motion, we have the equation
M₂ + E₂ = S where M₂ is the mean planet here or the
Mandasphutagraha or planet rectified for the equation of
centre, (by the equation M₁ + E₁ = M₂, M₁ being the original
mean planet and E₁ the equation of centre) so that δM₂ + δE₂
= δS where δM₂ is the mean motion here, δS the true
motion and δM₂ is the variation in the S'īghraphala; but at
a₁ and a₃ E₂ the S'īghraphala being maximum δE₂ is zero.
Hence δM₂ = δS which means that the mean motion is
itself the true motion.
Verse 34. Latter half, 35 and 36 former half.
The mean planet rectified for the equation of centre or
Manda-phala is called Mandasphuta. Then subtracting the
longitude of the Mandasphuta from that of the respective
S'īghroccha, the result will be the S'īghra anomaly from
which the S'īghra-phala is to be obtained. Rectifying the
Mandasphuta for this second equation namely S'īghraphala,
again obtaining therefrom the equation of centre effecting
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