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

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(x + y)/2 - y = (x - y)/2 where x is the previous interval AB
and (x + y)/2 is the H sine difference at B. Hence the argu-
ment is "If for y, there has been a decrease of (x - y)/2,
what will it be for δ (Here δ = 7·72) "? The answer is
δ ((x - y)/2) × 1/y = δ/2 (x - y) × 1/y = अवशेषकार्धम् × गतैष्यान्तरम्
÷ एष्यम्. This result is to be subtracted from (x + y)/2
i.e. ·2 is to be subtracted from 19·5 to give the rectified
H sine-difference.
Verse 18. Definition of Kēndra and assignment of
sign thereto.
The excess of the longitude of the mean place over
that of the apogee or aphelion as the case may be is called
the mean anomaly. The excess of the longitude of the
point called Sīghrōccha over that of the planet rectified
by the first equation known as Manda-phala or equation
of centre is known as the Sīghra-anomaly. The equation
of centre is positive or negative according as 180 < m < 360
or 0 < m < 180 where m is the mean anomaly. The case
will be reverse in the case of the sign of Sīghraphala, the
second equation.
Comm. “चन्द्रसूर्यौ स्फुटौ स्यातां मान्देनैकेन कर्मणा” i.e.
The Moon and the Sun could be rectified by the equation
of centre alone. This means that the Moon revolving
round the Earth directly and that the Sun revolving rela-
tively round the Earth are subject to only one correction
namely the equation of centre for rectification. In the
case of the Sun, though the fact is that he is revolving
round the Earth relatively, assuming as Hindu astronomy
does that he is revolving directly round the Earth and
subjecting him to the correction of the equation of centre