Page:English translation of the Surya Siddhanta and the Siddhanta Siromani by Sastri, 1861.djvu/27

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Súrya-Siddhánta
17

the given arc which falls in the quadrant where it terminates, but the sine of the Koṭi (of that arc) is the sine of that arc which it wants to complete the quadrant where the given arc ends; and the sine of the Bhuja (of the arc) which ends in an even quadrant (i. e. 2nd and 4th) is the sine of that arc which it wants to complete the quadrant where the given arc ends; but the sine of the Koṭi (of that arc) is the sine of that part of the given arc which falls in that quadrant where it terminates.

To find the sine of the
given degrees &c.
31. (Reduce the given degrees &c., to minutes.) Divide the minutes by 225: and the sine (in S'lokas 17—22) corresponding to the quotient is called the gata (the past) sine, (and the next sine is called the gamya to be past sine): multiply (the remainder in the said division) by the difference between the gata and gamya sine and divide the product by 225,

32. Add the quotient to the sine past: (the sum will be the sine required). This is the Rule for finding the right sines (of the given degrees &c.) In the same way, the versed sines (of the given degrees &c.) can be found.

Given the sine to find its
arc.
33. Subtract the (next less) sine (from the given sine); multiply the remainder by 225 and divide the product by the difference (between the next less and greater sines): add the quotient to the product of 225, and that number (which corresponds to the next less sine); the sum will be (the number of minutes contained in) the arc (required).

Dimensions of the 1st
epicycles of the Sun and
Moon in degrees of the de-
ferent or concentric.
34. There are fourteen degrees (of the concentric) in the periphery of the Manda or first epicycle of the Sun, and thirty-two degrees (in the periphery of the 1st epicycle) of the Moon, when these epicycles are described at the end of an even quadrant (of the concentric or on the Line of the Apsides.) But when they are described at the end of an odd quadrant (of the concentric, or on the diameter of the concentric perpendicular to the Line of the Apsides) the degrees in both are