AD DVO CENTRA ATTRACTI. i6i 

 Confeqiicntcr acquatio fcparata ita crit comparara : 



dr ds 



V#m(rr-iXi(B-»-A)rf Cirr-.)+ --O-jrr) - V.in(.-ss;(2(B-A)!-+-C(i-sS;-.D)— :js) 



yndc per qiuidratiiras relutio intcr binas variabiles r 

 et X definiri poteft. 



28. Statuamus breuitatis gratia : 



y(OT(rr-i)((B + A)r-f-^C^rr-i)-|-D) rr) = R 

 y(/K(i-xj)((B-A)x+i-C(i-xj-)-D)-xx)iz:S 



vt aequatio noflra feparata fit j -^ — -^ , 

 ct binae praecedentes aequationes ficnt : 



rFF^)T(,— «). — R R^(|)' feu d<^ = (7V::r,)(, --rs)R 



(r r — Si)* d I' 00 J/iN' /- J/K (^ r — s s) d * 



(FT^)»T.":iT^* = SSrfCp- feu rtfcp _ (TTTnjuTriTTs 

 bincque elemcntum tcmporis ob 



aww=:layam.{rr—t){i — ss) 

 ita exprimetur :. 



dr-laVfnaJ'-^'-^ yt\ dx-laVfna/^'^-^'. 



29. Vt etiam iingulus (p pcr formulas fim- 

 plicitcr integrales exhiberi pollit , binarum formula- 

 rum differentialium pro d(p inuentarum prior mul- 

 tiplicetur per fVE:~ pofterior \ero per ff^-j; , et 

 produdorum fumma dabit :. 



d(p-(pir:r,y^ + (~irs ideoque Cl)=/(~iTR+/(T:^s 



fimili moio ob t~t pro tempore fiet : 



<it- ^ ^ R -T-jideoqHe-r::-^^/-^^ — J -^) 



quiie 



