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

120 (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