vnde pro cafu z — c flet Z — o , quocirca pro praefenti 

 cafu, vbi p — c, erit P — o. Deinde autem fi loco q ibi 

 fcribatur — q, fiet 



Q_= c' y{c c — q q) {C -{- {a a — c c) q q). 



§. 27. Sumtis autem litteris ^ et r negatiuis, 

 cum in genere inuenerimus 



r — =-^c^, ob /) n c et P =z o fiet 

 — r—- — =^-% — , ideoque 



f ~ "'' "^^'^'^ - T?) ;c*-<-faa^;-_cc)_£g) 

 et -t- (ao — ccj 95 ' 



quo valore inuento erit difFerentia arcunm CR — AQ fiue 



n:c~U:q-U'.r = ^.pqr- ^-^ .qr; 



quamobrem fi loco r valorem inuentum fubftituamus, ha- 

 bebimus 



P R A rv (g g — cc) q ^/\cc — g q) (c* -^- {aa — cc) tjq) 



V> IV — i\ ^; ■ ro^-H (aa - ccj qq) ' 



Hic igitur quantitas q arbitrio noftro efl relida, vnde ar- 

 cum AQ pro lubitu affumere licet, hincque pundlum R, 

 feu appHcata Rf— r, ita eft detcrminata, vt difFerentia 

 arcuum CR — AQ fiat algebraica; formulae autem inuen- 

 tae manifefto reducuntur ad has fimphciores ; 



r ec ^/(cc — qq) 



y(c» + (aa — cc) q.i) ' 



ct difFerentia arcuum 



n P /^ Q — {aa — cc) q V[cc ~ qq) 



■vbi notetur effe arcum 



\ ri f dq V(c* 4- (aa — cc)<fq) 



*^ ^ J 6 y(cc — qq) 



§. 2$. 



