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

152 But PM is the H sine of m¹ where m¹ is called Sphuta- kendra (m is called the madhya-Kendra). Hence H sin m¹ = R/K × M₂N = R/K × Bhujajyā (in the eccentric) ∴ m¹ = H Sin⁻¹ (R/K × Bhujajyā) = PA₁ ∴ M₁P = Sīghraphala = M₁ A₁ — PA₁ = Kakshya- mandala Bahu minus the chāpa m¹ — Here a clear under- standing of the word Bāhu or what is the same Bhuja should be had. The arc pertaining to the angle m in the eccentric is known as the Bāhu in the eccentric and that to the angle m in the deferent as the Bāhu in the deferent. When 0<m<90, m is itself spoken of as Bāhu; when 90<m<180, 180—m is spoken of as the Bāhu; when 180<m<270, m — 180 is the Bāhu and when 270<m<360, 360—m is the Bāhu. Thus the Bāhu is that angle whose H sine will be H sin m numerically. When it is said in the verse ‘त्रिज्याहता कर्णहृता भुजज्या’ the word Bhuja is the arc M₂A₂ as is mentioned in the same verse ‘ज्ञेयोऽत्र बाहुः प्रतिमण्डलस्य’. The second part of the verse divides the eccentric circle into such quadrants that in them S'īghraphala increases from Zero to a maximum, decreases again from a maximum to zero, again increases from zero to a maximum and again decreases from a maximum to zero. Thus at A₂ of the eccentric the S'īghraphala is zero; at a₁, it is a maximum namely the arc b₁c₁ where H sin b₁c₁ = a₁c₁ = r; Thus in the course of A₂a₁ the arc of the eccentric the S'īghraphala gradually increases from zero to a maximum and in the course of a₁a₂ the S'īghraphala decreases from a max to zero. Again from a₂ to a₃ it increases from zero to a max and from a₃ to A₂ it decreases from the maximum to zero. Thus the quadrants in the case of S'īghrapbala are not of 90° but arcs A₂a₁, a₁a₂, a₂a₃ and a₃A₂ which are respectively of mag- nitude 90° + H Sin⁻¹r, 90 — H Sin⁻¹r, 90 — H Sin⁻¹r and 90+H Sin⁻¹r. In the case of Mandaphala also, the quadrants should have been of the same magnitude if the so-called Karnānupāta has been postulated i.e. reducing the Manda-