+8 DE EXTRACTIONE RADICTM 



§. 36. Ex his fcilicet , fi dcbito modo applicentur, 

 patebit , y fore radicem potefhitis n ex x , polito X d;\- 

 ri per hanc aequationem cubicam : 



x s -\- a x' -\- b x -{- c — O 

 Si coefficientes hiuus acquationis 



f -+- pr -r- qy H- r = o 



fequenti modo determinentur : 

 I. Cafu quo n = i 

 d = /> 



* = jf 

 f — r 



II. C:\fu quo h r: 2 

 rf = — pp -f- 2 q 

 b = qq — 2 p r 

 c = — rr 



III. Cafii quo n = 3 

 d = p J — 3 Pl -\- 3 r 

 bzr.q' - 3 pqr-\- 3 rr 

 c = r 1 



IV. Cafii quo « — 4 



* := />M- 4 M <7 - 4- /> >" - * <7<7 

 bzzq*— +pqqr-\-+qrr-\-*pprr 

 c zzz — r* 



V. Cafu quo B = 5 

 a—p s -sp'q-\-spprr-\-$pqq-sqr 



b — q^-sp^r-^-sqqrr-^-sfqr-Spr 1 



c = r 5 



VI. Cafu quo ;; = 6 



a--p 6 -\-6p*q -6fr -yppqq-Y I2pqr+ iq-«rr 

 b~q 6 -6p q< r\ 6q z rr-\-$p 2 q' r'-i 1 pqr z -2p'r-\-3 r* 

 < = -r 6 §. 37. 



