C V R V A R V M. 53 



o — -h dx (? -)- Sy ~f- £ J7 ) -f- X dx (y -H 2 e/ _f- <^ j/j/) 

 — ^A\g-|-<5"A'-|-eA'.v) —ydx y-\-zzx-\-^xx) 

 + i/x (g -H ^ jr -+- e A- .r) -h / </x f y-|-2 e .v 4- ^ .va") 



vnde </.v per ds ita dcfinietiir , \t fit : 



"•^ ^[x—y]-^' xx~yy)~y,x^^, ^^xy(x—y) i^^^Q 



j , di S-j-S x- ^- exx -i- yiy-i ^- i x-t-i^ X X ) 



quo Y:ilore fiibftituto fict : 



,T7 cp-a)d» 



«V — (^x—y)[S — y-^t[x-i-y}.i-^xyY 



18. CuiTi P ct Q fiiit fiiniles fiindiones ipfli- 

 rum .V ct jy manifclhim cl^ P— Q_ per x—j fore 

 diu fibile , et fni(flioncm ^^^3, vtramque variabilcm 

 X et y acqualitcr efle complexuram. Qiiia \ero 

 pofuimus x-f-J — •«■> ponamus infuper xj — t, vt 

 fit: 



jy P — Q - ds_ 



•' * K—y' 5 — y-^-is-t-it' 



At ob xx-\-yy~ss—i.t aequatio canonica induet 

 hanc fc)rmam : 



o — ci-\-2?s~\-yss-\-2($ — y)t-\-2esi + ^tt 



cx qua clicitur : 



-S -^-y-is^^/':S-y)^-a ^ +.2(S-y'is — ^€^ s.i-tiis — y^it) 

 t _ __ ^ - - 



ita \t fit : 



^-Y+ex + ^f = y((^-Y;-a^+^(('^-v)£-^'^)^ 



Statuamus hanc formulam irrationalcm : 



y[^$-yy-c,^.^2[[S-y)t-^^]s-{-^zt-y^)ss)-S 



G 3 \t 



