quo Talore, ob A=rs, in noflra^^qTfjttmnBTubflituto- for- 

 mula finiflrorfum pofita jeuera cuanitura erit. 'Ad hoc 

 oflendendum ponatur 



z — ^-"" (C cof X ?H- D fin. X 



eritque differentiando et per d t diuidendo 



|^=-i«^-™'(Ccof.X/4-Dfin,X/J4:Xf^'"'(Dcof.Xf-Gfin.X^] 

 fiue 



j|f— ^-""((XD-wC^cofXr-fXC^-wDjfin.X^). 

 •Hinc iterum li differentietur, prodibit: 



^^i=e-'"'(((m'-X^)C-2XwD;cof.Ar+(w=-X=)D+2X;«C}iln.X?) 



=-^=:e-'^'((2;7^XD-2^;/'C)cofXr-(2XwC4-i»rD}fin.Xx) 



fiz — e—'^^ (wCcof X?-f-«Dfin.XO 



quibus ordine coHecfcis aequatio noflra hanc induet formam: 



«Jd« . «™45 , ^^_,-m,5 («-w;w-XX)CcofXr^ 



"^^ ^''^''"- 7+(«-';;/;;/-XX)Dfin.x4 



cuius pars dextra ob W — n — m m manifefto in nihilum 



abit. 



§. 16. Ceterum hic maximi momenti eft obferua- 

 tio , quod fi pofito z—p formula illa finiftra prodiiffet 

 rrP; tum vero pofito z~q fuerit formula — Q et po- 

 fito z~r formula fit =R; tum pofito z~ p -\-q~\~ r 

 femper fore formulam finiflro loco pofitam =i P-f- Q-|-'R, 

 cuius rei ratio manifeflo in eo efl fita , quod in hac for- 

 mula valor z eiusque differentialia -vbiqLie vnicam habeant 

 dimenfionem, ita vt haec regula pro omnibus valeat for- 

 mulis , in quibus dimcnfionum numerus vnitatem non fu- 

 perat. 



§. 17. Nunc igitur inuento valore partis ihtegfafis 



A, quaeramus alteram partem T, cuius forma, vti aequa- 



fionis naturam perpendenti facile intelligendum erit, de&et 



'«ffe Tzi/fin. <r/ + ^cof.^;; tum enim pofito z—ffinct 



Ma Acad. Imp. Sc. Tom. L P. //. N + 



