144 DE CRITEKIIS INTEGKABIL. 



ax^i ■^:^x....,f j 2.3.^«-3 ^ ^1.2.3.7/2-2 



+ ^ Na,''^"'^- 



1 . 2 . , «; — I ' 



II. Confidercmns inm huiiismodi formulam 

 differeiitialem dxfS dx^ pofito quod fit 



dy — mdx-^^dy-^Vdp-^Qdj . . . . 4-U</« 



et inquiiamus , quibus requifitis haec formula difie- 

 rentialis inftruda effe debeat , vt de ea affirmari 

 poffit , quod integrabilis fit. Primum itaque fi po- 

 namus /V fl^.v — V, liquet ad integrabilitatem for-- 

 mulae \'dx requiri , \t formula/V^.v verum fit 

 integrale , quod iam obtinebitur , fi fequenti fatisfiat 

 conditioni 



d P ddq ^ /R d^ _ 



d X d X d X — d X 



Qiium vcro hoc crlterium tantum declaret formulam 

 \dx effe integrabikm feu V verum effe integrale, ad 

 integrabilitatem formulae V^^.v diiudicandam , aliud 

 infuper requiretur criterium fequenti ratione facile 

 dctegendum. Statuamus effe 



^V'--MVa'-i-N'^j^-hPV/) -f-TVr 



tum autem criterium integrabilitatis formulae Vdx^ 

 hac continebitur aequatione 



d V ddQl / R' _ d^V __ 



At 



