IMAGINARIIS CONSTRFENDIS. 187 



Similiter pro Dto ^ feu VQvr erit 



X* =~\p'-q-\- py{lp*~r-x) rr Driim ?Qyr=— Dtnm PQVR 



-7r;.-[-y[-^/-^-/.y(i/-i-^)]-f-V[-^/.'-^-H/»y(i;;'+^)]].'y[-;p'-^-|-/y('/-+^)l 



=^-[-^P'-^-^pAip'-^^)]-^^^/ 



■rzz-^-^p^-^-q-pyHp^-^-q) +^— -DtiimPQ^^r-aPI-yiR— -f DtumPQyR+ oPIfr. 



-q~ —q — -fcjPI-viR— -dVUr. 



quorum fumma vtrobique eft nz o. 



$. 18. Tertia aequatio erat x^-\-px-\-q—o ; adeoque eius deinceps pofita 

 cft -{x^-^^px-vql—o , feu -x^-px-q—o^ yel A''-+7r.v-i-^rro. Ad hanc conftruen- 



damfit(F/^.3.)rubY),^p^^:^H/>,et ^^^^'J^ .= -V(l/>'-^)i Fig. 3. 



€rit SP/=P^4-^ /•?__, y/.^»_.x \ 



m—?a-\-a6~' '^ ^'^ ^^ I fumma— -/);faa;um— |/-(i/-^)r=-}-^. 

 et 5P/-P^-^^^._.p+y(.p^_^)| .□P;>=oP^2^. 



hinc Dtum maius Vifkz=:lp^—q-\-py{lp*—q) 

 Dcum minus Vqir—lp*-q—py{lp'—q) 

 Ergo pro maiore Dto (5" , fcu pro PK/r erit 



/*=-[i/)"^-^-f-;)V(^/>-^)]--i/-+-^-/,y(^/-^) 

 eiiisquc radix .vr=y DtiPKirzr— y[-i/)*-f-^-py(i/)*~^)] (§. VIII). 

 Pro minore Dto § , feu pro P^^ifR erit 

 x'--{^'-q-py{-p'-q)]--lf-\-q-^pV{^p'-q) 

 eiusque radix .vr=y atiP</-ii;R=*-y[-'/)'-+-^-f/)y('/,*-^)] (§. VIII). 

 fldcoque fumnia radicum (quam pono rz; — tt), fed contmrio figno affcda 

 —-hTT-.-^y[-lf-\-q-pV{ip'-q)]-]-y[-:^p'-\-q^py{'^p'-q) 

 ct ficlum —-y^-lp^-i-q-py^lp^-q^l-yi-lp^-h-q-i-pyilp^-q)] 



=+n{<f'^qy-p%f-^)]^+y[lp*'fq-\-q-lp'-\-p'q]--\-yq' 



--^q. 



A a a Ergo 



