Surya Siddhanta
मध्यलग्नार्कविश्लेषज्या छेदेन विभाजिता। रवीन्द्वोर् लम्बनम् ज्ञेयम् प्राक्पश्चाद् घटिकादिकम्॥
The sine of the difference between the place of the Sun and the nonagesimal divided by the chheda gives the Moon's parallax in longitude from the Sun reduced to (sávana) Ghaṭikás, whether the Sun be east or west (of the nonagesimal.[2]) [2. All Hindu astronomers suppose that every planet daily traverses 12000 yojanas nearly in its orbit and as the part of a planet's orbit intercepted between the sensible and rational horizon is equal to the earth's semi-diameter (or 800 yojanas which = 1 / 15 th of 12000) therefore, the extreme or horizontal parallax of a planet is thought to be equal to 1 / 15 part of its diurnal motion: thus the Moon's horizontal parallax is 52′ 42″ nearly and the Sun's 3′ 56″ and hence the horizontal parallax of the Moon from the Sun is = (52′ 42″) − (3′ 56″) = 48′ 46″. And four Ghaṭikás in which the Moon describes 48′ 46″ from the Sun is the horizontal parallax in time. Now, let l {\displaystyle l} = the latitude of a planet (the Sun or Moon), d {\displaystyle d} = the difference between the places of the planet and the nonagesimal, a {\displaystyle a} = the altitude of the nonagesimal, p {\displaystyle p} = the horizontal parallax, x {\displaystyle x} = the parallax in longitude, y {\displaystyle y} = the parallax in latitude. Then we have the equation, x = p sin a . sin ( d + x ) R . cos l ± y {\displaystyle x=p{\frac {\sin {a.}\sin {(d+x)}}{R.\cos {l\pm y}}}} which is common in astronomy.]
english translation
madhyalagnArkavizleSajyA chedena vibhAjitA। ravIndvor lambanam jJeyam prAkpazcAd ghaTikAdikam॥
hk transliteration by Sanscript