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

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In the parallel great circle, the Equator we have
therefore Antyā = Charajyā + R (already derived).
Verse 35. Antyā = (Hṛti × R) / (H cos δ) = (Hṛti × Charajyā) / Kujyā and
∴ Hṛti = (Antyā × H cos δ) / R = (Antyā × Kujyā) / Charajyā by what is
called Guṇa-ccheda-Viparyaya ie. alternando.
Comm. Evident.
Verse 36. To obtain Dinārdha-Śaṅku from Antyā
and Hṛti
(Antyā × un-maṇḍala Śaṅku) / Charajyā = (Hṛti × 12) / K = Dinārdha-
Śaṅku.
Comm. The second formula is derived from the
similarity of △ Ao₄a (fig.) with the first latitudinal triangle.
From the similarity of Aao₄, Ddo₄ fig. 39,
Ao₄/Do₄ = Aa / Dd ∴ Aa = (Hṛti × unmaṇḍala-Śaṅku) / Kujyā .
But Aa = Dinārdha-Śaṅku
∴ Dinārdha Śaṅku = (Hṛti × U.S.) / Kujyā (U. S. = Un-
maṇḍala-Śaṅku.)
But Hṛti / Kujyā = Antyā / Charajyā
∴ D.S. (Dinārdha-Śaṅku) = Charajyā / Antyā × U.S.
= (Hṛti × 12) / K VIII.
Verse 37. Meridian Zenith distance.
Agrā ± (Hṛti × bhuja of a lat. triangle) / (Karṇa of a lat. triangle) = H sin z
where z is the meridian zenith distance.
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