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

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∴ sin ν = (sin ω cos λ) / (cos δ) or H sin ν = (H sin ω × H cos λ) / (H cos δ) II
Comparing I and II, ν would be equal to δ′ provided
H cos δ = R. This is accepted as an approximation, as
δ is generally small.
This approximate formula is given by Sūryasiddhānta
in the context of Āyana Dṛk-karma in verse 10, ch. 7,
where ν is assumed to be equal to δ′ defined above.
Verses 4 and 6. The process called Āyana Dṛk-karma.
The Āyana Dṛk-karma correction measured in minutes
is obtained by multiplying Āyanavalana by the unrectified
celestial latitude, and divided by H cos δ and then
multiplied by 1800 and divided by the rising time of the
Rāśi which is occupied by the planet. Or again it is
obtained approximately by the product of the Āyana-
valana and the unrectified celestial latitude divided by the
Yaṣṭi.
This Āyana Dṛk-karma correction is negative if the
hemisphere and the latitude have the same direction.
On symbols, Āyana Dṛk-karma correction =
(Āyanavalana × β × 1800) / (H cos δ × T) or approximately equal to
(β × Āyanavalana) / (Yaṣṭi (= H cos ν)) .
Comm. Let G be the position of the planet when the
foot of the planet’s secondary (called Grahasthāna) to the
Ecliptic namely A is rising, where rCA is the Ecliptic.
Let rML be the celestial Equator. Let P and K be the
poles of the celestial Equator and Ecliptic respectively.
The arc AC of the Ecliptic intercepted between A and the
declination circle of G expressed in minutes represents the
आयनकलोः formulated in the verse. To find the magnitude
of AC, the first formula mentioned above envisages finding