पृष्ठम्:चन्द्रछायागणितम्.djvu/३०

चन्द्रच्छायागणितम् (The Sec011d-Ime१uatity-C0rrection) 3. Thc R cosine of the 'true sur1-7॥i॥५७-m100n's apoge' X R sine, or R cosine, respectively, of the eduation of the 'centre-corrected m00n-11irus-true Sun' x the eguation of the 'centre-corrected-1901's daily motion'–:- (20xR x the moon's daily mearn motion) is, respectively, the moon's bht]ja-phala and koti-plhald 4. Add to or subtract from R, the koti-plala according as the 'true sum-71i115-moon's apoge' and the 'cguation of the centre-corrected moon-72inux-true sum' are both in the same a y201a (i.e., from 90° to 270* or from 270* to 90"), or in different ()'a70s (i.e., (one is from 90 to 270° and the other is from 270° to 90°). Suare this and add to the square of the bluja-plhala. Find the square root. This is the "Last Hypotenuse 5. R x bht!jd-plala -- the 'Last Hypotenuse ' is to be added (or subtracted from the euation of the 'centre-corrected-me001', as the 'true sum-7irus-apoge' is from Cancer or Capricorm, (i.e., between 90° and 270', or between 270° and 90") if it is the light fortmight (i.e., if 'no n piru७-sum' is between 0" and 180°) . Reverse the addition1 and sub traction if it is the dark fortunight (.e ., if 'Im10 -11irtus-sun' is between 180° and 360-). 4. This is called Evection . First, Vatesvar॥ (904 A.D.), then Muljala (932 A. D.), and after him Sripati (999 A. D.) gave this correction in Hindu astronomy.