VARIATIONVM TMACTANDI. 6i 



43. Non igitur pigcbir in tnlcni cxpre{Tioncni 

 Z inquirmiflc , nc prinio quidcm patct cani practcr 

 coordinatas x ct y ciiam q^uuitifJtcm. p inuolucrc 

 dcbcrc. Sumamus autem practcrca in Z non ingrc- 

 di litteras q, r ctc. ita vt fit Q_— o, R — o, ac 

 nollra acquatio reroluenda crit : 



pZ-ii ^pp)?, 

 Tbi notandum cft efTe 



^ Z — AW A- H- N dj -{-Vdp, 



quare fi ambac coordinatac x et y tanquam conflan- 



tcs trac^rcntur cric 



dZ—Vdp idcoquc P — 11 , 



quo valorc ibi introdudo haec prodibit aequatlo 



d Z td^p^ 



z — ri^-pp 

 quac integrata dat 



L.Z-L. V(i ^pp)^h.C 



quae conHans fundio quaccunque ipfarum x et y 

 efTc potcft , talis fundio fit V atque habebimus 

 Z=:Vy(i_|-pp), 



ideoque formula integralis 

 z=if\dxV[i^pp\ 



Huius formulac flgnificatum fatis clcgnnfcr pcr tcm- 

 pus , quo corpus quodpiam per curuam A M pro- 

 mouctur exprimi potcft. ^i cn'm tcktitus in pun- 

 clo M, fucrit — V , hoc cn fi cdciita.s in fingulJs 

 H 3 puudiis 



