ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

BHĀSKARA II ON INEQUALITY OF THE MOON 119
The reasons for his new equations are stated as follows:—
When the Moon is situated at a quadrant ahead of
the apogee and with the Sun at half a quadrant ahead
of her, the maximum discrepancy (of 112′) is seen in the
negative character.
When the Moon is situated at three quadrants ahead
of the apogee and with the Sun at half a quadrant
behind her, the maximum discrepancy (of 112′) is seen
in the positive character.
When the eclipses of the Sun and the Moon take
place at the apogee or the perigee of the Moon, the
Moon as corrected by the equation of apsis is seen to be
without any new correction called bīja.
When the eclipses of the Sun and the Moon take
place at the ends of the odd quadrants of the Moon's
anomaly (measured from the apogee), the discrepancy
is seen to be less by 34′.
When the Moon is at the apogee, whether the Sun be
ahead or behind her by half a quadrant, the discre-
pancy amounts to be 34′.
The same discrepancy of 34′ is observed when the
Moon is at the perigee and the Sun is ahead or behind
her by the same distance.
Thus by analysis and synthesis, and by repeated obser-
vations, this variable correction has been devised by
me; let it be seriously considered by the learned.¹
Bhāskara here speaks of six cases and we consider them one
after another :—
The Moon's equations as modified to suit siddhāntas are
given by
−301′ sin (nt—α)+13′ sin 2(nt—α)......
−152′ sin (nt—θ) cos (θ—α)−40′ sin 2(nt—θ)+......
According to Bhāskara's Siddhānta - śiromaṇi. the Moon's
equation of apsis
= − (31° 36′ / 360°) × 3438′ sin (nt—α)
= −301′ 46″. 8 sin (nt—α),