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

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from the sign itself without an appeal to a picture or
without ascertaining whether the northern Agrā prevails
over the Southern Saṅku-tala or the Southern Saṅku-tala
prevails over the northern Agrā. Thus the Dinārdha
Saṅku in symbolism = H cos (φ ± d) (20).
Verse 33. Here at noon, Dṛg-jyā is the H sine of
nata and the Saṅku is H sine of unnata.
Second half of 33 and first half of Verse 34.
The product of R and the unmandala-Saṅku divided
by Charajyā is called Yaṣṭi. The Yaṣṭi increased by
Un-mandala-Saṅku gives H cos z according as the Sun is
north or south of the equator.
Comm. Unmandala-Saṅku is H cos z when the Sun
is on the unmandala. From the sixth latitudinal triangle,
wherein Unmandala-Saṅku is Bhuja and Krāntijyā
Karṇa, so by comparing with the second latitudinal
triangle (or rather operating with the second triangle to
signify the Hindu method).
(Krāntijyā × Bhuja) / Karṇa = Unmandala-Saṅku
= (H sin δ × H sin φ) / R (already derived under (19)).
We saw before Charajyā = R tan φ tan δ. Hence as
directed in the verse (R × H sin φ H sin δ) / (R × R tan φ tan δ) = Yaṣṭi
= (H cos φ H cos δ) / R (21).
∴ H cos z (at Noon) = (H cos φ H cos δ) / R ±
(H sin φ H sin δ) / R according as the Sun is on the north or
south of the equator.