52 DE SFPERFICIEBVS 



^ — -f-R. Sed -^cfx' \-^-exz-^/,^^-^ac:z^-{-^f 

 bx-44-gz^K^ , praebet /;c» =exz-{- -'-^'z^ -f- bx 

 ^gz- ^c^^ y ^^ extrahendo radices zJx-z^ez-^-b-A^V 

 {e-'^^^^z^-^ ieh- ^jg.z-^h^-iK^)~Sit 

 jnunc c^4_-i±^/-=/g-i^'^ et fubftituatur hoc in fu- 

 periori aequatlone {ce^ — ^ac-f-i-lf-f)z^:zi{^cfg-2c 

 eb)z--ch\imi£metur(^^f^)- z^-2{ t2.fg-eh)z-\-b^ 

 zzOy et extrdiendo radicem ~^^ z — h~o^ quare k 



— Hi=^> ^'^ 2/^-^^==fe"» propterea fit — V^^ ^ 



(j— — V~>— pr qui lupra in y( ^-—^z^ -^- 



^b—^fg. z-i-b^ — fK^) fubftituta , producunt zfx— 

 fZ-+-b±y{'^f-^-^h'-{K^), et proptcy rj-k 

 —Zy fit 2fx—ez — b=z-^y{'']^J—-^-f). In hac vero 

 polita ^ — pro ey tt deinceps ftatuatur ^j; — /2; — ^i?^ 

 aequatio abit in =i^^- h- V(^r-^r), et qua- 

 drando ^^,- — '~kr~~^ W — 'W ~V 1 quare dele- 

 tis delcndis ct rcduda aequatione inuenitur R 2 — i^^^^^i^^^f 

 < — ^^ — , quare diuila hac .lequatione per -p- -, i"e~ 

 Miat Mtique c- q- zt- h p —fp^ ^ aequatio ad Ellipfin^ 

 exiftentibus AE:^:^,, et EF" ^. 



Binae vero aequationes 2cky-h^kz—zc^v^et 

 kx — lzzz:pv y fum ad lineam reclam VF ex Coni 

 vertice V ad punchim bafis F ducftam. Agatur enim 

 DC paralleFa VP, et DS aequidiftans FP; habebimus 

 DC.VP;:FC.FP,::EB.Eq, id cft DC (;s). VP(yt):;EB 

 {x-p).EQj^l-p): liaec amilogia pracbct bx — lz — pv. 



raiicer 



