

— (90) = 



j^irqiic dcmonflnitum crt ambas littcras p ct q fcmpcr inter 

 lc clic pcrmutabilcs. 



§. 7. His pracmillls, quo calculos fcqucntcs rhagis iii 

 compcndium rcdigcic liccat, loco formulac huius iutcgralis : 



/* x^ — ' r").v r x''-' dx 



^ / (i — xV"'' F (i — JfV 



fcrlbamus hunc characflcrcm: (/>, 7), \bi pcrindc cfl, fiiie p anrc 

 (/ , iiuc (/ antc p coilocctur ; fcmpcr autcm hic ccrtus cxpo- 

 nens n fubintelligi dcbct. Hic autcm duo cafus prac rcHquis 

 maximc mcmorabilcs occurrunt. Prior cafus eft, quo numcro- 

 rum p ct (/ altcrutcr ipfi cxponcnti « cft aequalis; fi euim fu- 

 erit q — n^ crit ex priorc formula (/>, ;/) zr. /.v^~' r) .v ~ » , 

 ficque perpctuO habcbimus (/), «)— |,, hincquc ctiam (w, q) 

 = ;'. Altcr cafus notatu dignilfimus locum habct , quando 

 p -^ q nz Tj ^ quo cafu femper cfl 



n n 



Ad hoc of^endcndum fit q =i fi — p-, hincquc formula propo- 



r x^~' d X v 

 fita / : , tum ponatur ^^^5 ct quia 



' l"Vi— :v")p 1/(1-0 



_ =z% erit S= / -—-. 



iitionc fcquitur .v" z= — ^ , hincquc 



tx faifla autcm po« 



( 



I -H z' 



ri l X ::^ « / s ^ / ( I -H ~") ? 



crgo dilTcrcntiaudo 



jup nL ♦ D .v 



