FORMVL. DIFFERENTIALIVM. 173 



^ '^ y ^ ^ ^dTds^i ^ [d^^ ■+- (rfWj) __ 



\ d j3 / I \axdy' 

 30. Vltcrius erit : 



VI. Q-(.^LJL.\-~( d' T )_/ d^ S \ . f d^ R \ rddQ,^,/d?, AT 



VILo-(— ""- )-f-^^)-r-^^~)4-r '^' R^ /dda>. rdp^ xT 



''^^''-^-^dxidy^-^-\dx^dy ^dx* ^ ^\d~^J~[T^Wj^) — N 



^(dL^\Ji-(dlR'\_(ddQS.\,fdP'. 



^^'■^'^-'^dxHy^J-^dx^dy''' ^dx^dy^^^^l^ ) (ir^>'+ (d~«;) — N 



— C iL'_£l ) 4- r ilH) _ /dd q:^ 4_ /dP' \ 



^dx^^dy^^J ^\dx'ay^ \dxdy^'^dyJ 



JL.(d]_^')^(ddQi.'\ 

 ^\ax ay^J ^ d y^ ^ 



IX o-( ^' '^"' ^— ( ^^ '^"' \^(d' s," \. /d-- R^ 'I — ridQ.^4-/'^p^ -* M 



^^r^d;^^d>+'' — ^dx-dy^l ^dxHy-J~ Sd^^yl ^d^J^^Jlx) ^^ 



_r/ ^' R"* ^_( ddQL^ \ 



IC 0-r<^' -I^'^ (^^ '^""\ — / ^' ^"' \ 4, f d^ R" N __ / dd Q: n , /d_P\ __ ■jvj 



'^ "^\d;e'd>5/ — ^d* ci>*/ ^axdy^l ~ ^dxdy^J ^dxdy^^axl ^^ 



( d^ S"" \ \(d^J<^\ f ^ dQi' \xjd P\ 



Xl.O-r^l^'^-— f^-)--('^-^)4-('^^1---('^^')4-(^) — N 



\dxdy^' — W 35 ; ^dj+-'^^dj3; \dy^l^^dyJ, ^^ 



Hae igitur fex aequationes reliqua criterla integrabi- 

 litatis formuiae noftrae fuppeditabunt , eas Yero in 

 \nam fummam cuUigendo obtinebimus ; 



Y 3 ^N- 



