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

255 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.