x$^INVENTtO CVnrAWM MAXIMl MINIM. 



f, 30. Quo' igitilt hanc difFerentiam pro valore qui 

 cx fQ_dx oritur et elemcntis abcdef refpondet, inue- 

 niamus , difFerentiare oportet hanc formulam Qdx 4- 



I II III IV 



QJx-^-i^dx-^-^^dx-^i^dx fecundum rcgulam datam 

 prodibitque 



dQdx—-^- 



dx 



^ II II 11 ri ir 



dqdx-hqdx. cY-\-mdx. cy-V .cy-V.d^-^-y^^^^^^-^lf. 



III III m 1 m III m 

 dQJxz-l^ dx dq.cy-hqdxd^-m dx. d^->r-V -^^-^ 



IV IV IV I 



dQjix ~—L.dx dq. cy-\~L dx dq. d^. 



Hacc difFerentia nihilo aequalis pofita dabit ^- y ( -^^' — 



I II II III IV I 11 



slV-{-(Lq-i-M)dx-{L-hL)dxdq) — dh~-dV 



m I in IV I 



-\-iLq-i-M)dx)-Ldxdq)y quae aequatio comparata 

 eum canonica F . c y — {?-{- d? ) d $ dat 



I n I m IV 



d? __ d'W-ddV d x-\- dx\ d[Lq-\-M.)-dx 'd.Ldq-^Ldx'dq 

 "p" — I ff II m. iv 



ddW-dxdV-\-dxKLq-\-m)- ( L-^L) dx' dq 



Hinc ergo intcgrando prodibit fequens valor ipfius 



r Ldx^ dq 



V — eJ ^<^^-^i^^--^^^^^^lddW-dWdx-\-dx%Lq-\-M)] 

 pofito vt hadcnus ^—57. 



§. 31. Ptrfpicuum igitur eft hunc valorem ipfius P 

 fedo Lz::o fore ddW - dV dx -\^ Md.V ^ ideoque noii 



diuer- 



