CALCVtl VAKIATIONVM. 71 

 Coroll. I. 



39- Qjiia rediidliones adhibitae quouis dafu f^cile 

 cxpediri pofTunt , iis prilctermiflls variatio quaefita hoc 

 iTiodo fuccindius exhibitur , pofito WzzzfLdx: 



<^/2^.v.= W^a-(5ZO^-^-i-^S->+^^+etc) 



-+-(a-SKW)f|.^-i-etc.} 



Coroll. 2. 



40. Ac fi quantitas Z inuoluat infiiper aliam 

 formulam integralcm n'— /gV.r, vt fit : 



dZ-Ldn-\-Ldn'-hMdx + Ndy-\-Vdp + Qdqi-etc, 



tum vero : 



d^^^r-^^dx-^-f^^dy-i-^^dp-i-oyq-^-di^dr-i-etc. 



Si ponatur /L^A"nW, JV dxzzV/^, iQfuperque ad 



abbreuiandum : 



N-g^W-S^^W^ — (N)-, P-^W-^'W^=:(P) 

 QrO,^ OyW^-^q^jR-SKW-StWr^CR^etc. 



erit variatio quaefita : 



iJZdx~Wldx{^§j+-^'^-+£l'f-li'\-m'/T^-hctc.) 



+w^jdx{<>si^sj+^^'^+o:'^-J+fK'7J+ctc.) 



+Jdxmh+-if)^+C(l)Tj+ (R)S + etc.) 



Problema 5. 



41. Si in formula JZdx qnantitas 2 praeter 

 litteras Xfj, p, q, r etc. inuoluat formulam integra- 



iem 



