FORMVLARVM DIFFERENTIALIVM. ^oj 



Pdtet autem coJem negotio multiplicatorem latius 

 quoqiic paccntem inucniri , qiiia eiiim eft 



idcoque fi ponatur ?i^|^ — -^, multiplicator ido* 



ueus fbrmulne propofitae , nunc quoque erit 



2^. -+. . 



(p — 7T-—--F- , ipfum autem integrale inde oriua- 



iv A," + o y 



dum eft ^Z'"-*-^ 



20, Confideremus iam formulam difFerentla- 

 lcm : 



dx{ci.-\-(^x-\- yj)-{' dy{$ -]- sx -i- ^ y) 



cuius fadorem per qucm multiplicata intcgrabilis 

 fiat , inueftigari oportet. Primum igitur liquet , fi 

 ftatuatur 



a-^-^x-^-yyzriz et B-^-ex-i-^y^zu 

 inde fieri 



(idxi-ydjzzdz , edx + ^dy — du 

 hincquc 



quibus valoribus fubftitutis noftra formula in hanc 

 traiisformatur 



{^ z - e u) d z ~\- ((^j u ~ y z) d u 



vbi quum iam quantitates , in quas dz et du du- 



cuntur, fint funflioucs homogencae ipliuum z et «, 



C c a per 



