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

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true parallax in latitude. This true parallax in latitude
increases or decreases the latitude of the Moon at the
moment of conjunction as is going to be mentioned in the
latter half of verse 14.
In deriving the parallax in latitude from the respe-
ctive Dṛk-kṣepas, instead of using the formula 4/R Hsine
(Dṛk-kṣepa) which is an expression in time, it is sought
to express the same in arc because the latitude of the Moon
is expressed in arc and we have to take the sum or differ-
ence of the latitude and the parallax in latitude to obtain
the apparent latitude of the Moon at the moment of
conjunction. In the case of the parallax in longitude we
sought to express the same in time because the moment
of apparent conjunction was sought therefrom.
Latter half of verse 12 and first half of verse 13.
An approximate method of obtaining the relative parallax
in latitude of the Moon with respect to the Sun.
The Hsine of the zenith-distance of the nonagesimal
pertaining to the Moon or what is called the Moon's
Dṛk-kṣepa multiplied by 2 and divided by 141, gives the
relative parallax in latitude of the Moon with respect to
the Sun ; or working with the smaller table of Hsines
(where R is taken to be 120) the Moon's Dṛk-kṣepa being
multiplied by 2 and divided by 5 and the result being
increased by 1/60th of itself gives approximately the relative
parallax in latitude.
Comm. Herein, the Vitribha or the nonagesimal of
the Sun is taken to coincide with that of the Moon. In
other words the Dṛk-kṣepas (the Hsines of the zenith-
distances of the nonagesimals, of both the Sun and the
Moon are taken to be identical. Then using the following
proportion "If by a Dṛk-kṣepa equal to R, the relative
parallax in latitude is equal to 1/15th of the difference of the