Porro vero erit p -f- </ z= A et p — q~'^-^ , hincque fiet 

 fr^^ zz z, exiftente v ~ — ^ , 



J. 2. Cum igitur fit z = tr^% erit 9 z ziz^JdAt 



■pdq) 



p -^-q" ^ (p. .q)a '^ 



vbi ob p-\- q —-^ erit dz=z:|2;t;(g5p — P^<?)- Delnde 

 vero , quia eft dp — — ^^ , erit qdp — pdq — — ^^ , 

 Simili modo, pofito dq — — ^^, erit qdp — pdq~^f„ 

 propterea quod p^ -\- q'^ :=i 2 ; ficque elementum d % duplici 

 modo, fcilicet per 3jo et per 'd q liabebimus expreffum, erit- 

 que primo 'd% — — '^'"^^ , tum vero d z — -t- 2i:^^-^ , quam 

 duplicem expreflionem per ^ z = 2; z; d w repraefentemus, exi- 

 ftente vel dw — — ^, vel dw— h-^. 



5. 3. Deinde vero ob \ -\~%znpv e\ i — %T=iqv 

 erit I — %% ~ p qvv, ideoque (i — % %Y zz: p'^ q^ v'^ y ficque 

 numerator noftrae formulae erit 5z(i — %%y — v^ppqqd(}:. 

 Pro denominatore autem habebimus i-{-%% — ^(pp-hqq)vVy 

 ita vt iam totus denominator fit ^v^ (p p -h- q q) , quocirca 

 ipfa formula noitra propofita ita repraefentabitur : 



8 V nz: z-v pp q q di^ — 4ppqqd(ji 



pp-^-qq (p -\- q ) [p p -i- q q)' 



Multiplicemus autem porro fupra et infra per p — q, vt 

 prodeat ifta forma: 



^ V — ' ^{p — q)ppqqd'» 



J. 4. Quoniam nunc numcrator ex duabus partibus 

 conftat, vtramque feorfim euoluamus. Pars igitur prior, quae 

 eft t^SJ^ , fi loco d(ii valorem priorem fupra datum fcri- 



bamus, fcilicet d w = — ^, erit ;= — ^-—^y quamobrem 



iv '■• ■ fi 



