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

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From I H cos δ / R = Kujyā / Charajyā so that
Kujyā = H cos δ / R × R tanδ tanϕ = H sinδ tanϕ III
In Triprasnādhyāya, the elements of all the eight
latitudinal triangles are found by using their similarity
with the fundamental gnomonic triangle. The important
elements that will enter into computation are (a) Charajyā
(b) Kujyā (c) Agrajyā (d) Taddhriti ie. S₁ F₁ the proje-
ction of SF on the plane of the meridian (e) Sama-Sanku
= E₁ F₁ = H sin EF (f) Krāntijyā = E₁ B₁ = H sin EB
= H sin δ (g) Lambajyā = H sin QS = H cos ZQ =
H cos ϕ (h) Akshajyā = H sin ZQ = H sin ϕ (i) B₁ D,
= Ud-Vritha-Sanku = H cos ZB (j) Dinārdha-Sanku =
H cos Zq. The following points will be noted.
(i) In the triangle E₁ Q G₁, the projected triangle
of EQG on the meridian plane, noting that E₁
is the centre of the celestial sphere E₁ Q = R,
QG₁ = H cos ϕ and E₁ G₁ = H sin ZQ =
H sinϕ.
(ii) S₁f₁ = H sin SB + H sin fB (both the H sines
pertaining to the diurnal circle.
(iii) Sama Sanku is the H cosine of the Zenith-
distance when the Sun or celestial body is on
the prime-vertical.
(iv) BD is an arc of the great circle ZB, so that the
Unmandala Sanku is the H cosine of ZB.
(v) Dinārdha — Sanku = H cosine ZQ.
(vi) These Sankus are the H sines of altitudes or
H cosines of Zenith-distances and they are in
the planes of the respective great circles.