124 DE METHODO 



deinde vero efl S^ziiSf'^ dx :=:f^3dx et B^^zf^^^^dx, 

 hincqne piopterea : 



^^^i^^j-hf^p^O^^^-hdi^r etc. 



cx quibus colligimus : 



S^ :=z fdxi^^j -h^ ^ p -\--0^ ^ i] -[-'^^ f etc.) 

 S^^=r.fdxm'$J'-i-^'^P'\~Oj^q-i-d\.'SrQtc.) 



Cum igitur fit variatio difFerentialis quaefita 



Bf Z dx =fLdx$<p-\-fL'dx$q)^+f^dxSj+f?dx$p etc. 



ponamus fLdx — V e.t fV dx — \\ eritque vc fupra, 



fLdx$(^~Vfdxm^j-^^$p-^OJq\^^rttQ.) 



-fV dx{^^j-\-9^$p-\-Ojqir^^rQt.c.) 



fL^dxd^—Vfdxm^Sj-h^^^p-i-Oj^q-i-di^^rQtc. 



-fW^dxi^'^j + ^'Sp-\-Oj^q-\-di'^retc.) 



Ponamus autem, h;iec integralia VczfLdx et V-zfUdx 

 ita cipi , vt eiiLinefcant , pofito A'zr:« , ac praeceden- 

 tium formularum partes priores (ponte in nihilum abi- 

 bunt , fiquidem earum valores pro termino x z=. a capi 

 debcnt. Omnibus igitur partibus coniungendis obtine- 

 bimus 



ZfZdx-fdx^j^V^-yi^-V'^') 



^-/^.r^^(Q.-va-v^aO 



-^-fdx^r^K-M^-V'^') 

 etc. 



Cum 



