(III) //r'( + vX + fJLY-Zfin.icor.r) 



-\-dg,'-{vX+ixY) 

 noti aiitem funt (equentes valores : 



— m d X — » dY — dZfin.i{in.r- — dx-{-y{dr-\-dQ,cof.i) 



— z d ^ fin. i cof r 

 lx.dX — y dY - — dx coCi-^-dzCin.iCitt.r—^i-^x^dQ^fin.iTm.rcof.r 

 -{-J.dQ, I— fint'cofr*]+^rcofij— z^^fin.icoficol.r 

 K X + [A- Y— 2 fin. i cof r — —y 

 nX — mY — —y cof t -f 2; fin. i cof r 



y X + fJi. Y — — y + 2 fin. cof r = ( i + jr) fin, i'fin.rcof r 

 ^^ **'' — J ( I — fin. i' cof >'') H- 5; fin. i cof i cof r ) 

 quibus coUedis erit 



,.,. ,,,,N -2^r^x +2^^^5;fin.ifin,r-(i+Jr)</^Tin.iTin.rcof r+j^r* 

 (llj+(iii j_^ 2 ^^^jccof t + aj^rr^S^coO 



-j<?"^'fi.i'cf.r' 

 — s a' ^* fin. i cof I cof r 

 quibus ad finiftram translatis prodit : 

 ddy-\-idrdx -id<^dzC\.\.C\.r-\-[i\x)dg,'C\,\H\,TzC.r-ydr^ 



'\-2ii^dxcoU —:!.ydrd^coC.i 



-ydQ; 

 -hr^^*fi..'cf.f* 



■\ z d Q; C\n. \ cof » cof r 

 =: - </ ?' ( V L + fjL M - N fin, i cof r ) 

 i^uae cum praecedente §._ii. exhibita pariter congruit, 



§, j6. Tertia aequatio erat 

 z = X iki, I fin, ^-Y fin. i cof. ^ + 2 cof. 1. 

 • quae bis difFerentiata dat 

 ACta Acad. Imp. Sc. Tom. 1. P. U. P p idx 



