•2-20 ŒUVRES DE FERMAT.- I- PARTIE. 



V, Z (Uu-aiilur taiii;tMitos EU, XS, YT, ZV, occurreiiles perpeiuliculari- 

 luis FX. GY, HZ, lA proiluclis, in punclis R, S, T, V. Ponatur i-ectse El 

 in (liircliiiii roc'ta IK lequalis recta' AR. 



Palet, ex pi'secedeiilc pni|»(isitioiie et ipsiiis cordllario, 



(liKuli-atuiii taiiiioiilis ZY ail (|ii;i(lraliiiii recla.' III 

 esse ul rectam IIK ail rcctaiii Kl; 



similiter 



ilcin 



(lenique 



Ml (|iia(lialiiin tanp:ciilis VT ad qiiailrnliim roda' (]I1, 

 ita reclaiii (ilv ail l'cclani Kl; 



f|iiailratiiiu laiigenlis XS ad quadralum recl;p V(\ 

 ut reclain FK ad rectani Kl ; 



ul (|iiadraliini laiii;ciitis EU ail quailrnliim rectic EF, 

 ila letlaiii EK ad reclain Kl. 



His positis, a piincto K excitetur KL perpendicularis ad rectam EK, 

 el fiât recta KL aequalis rectse Kl sive AB; intelligatiir jani per punc- 

 tiini K, tanquam verticem, axein aiitemKE, describi parabole siniplex 

 sive Arcbimodca, ciijas rectum laliis sit KL, et sit illa parabole K.MQ, 

 ad (iiiaiii exciteiitiir perpeiidiciilarôs EQ, FP, GO, HN, HI, (jiuv eriinl, 

 ut palet, applicata' paraboles el iii direclum posiUe perpendicuhuibus 

 F'X, (JY, etc. 



Quadraluin tangeiitis ZV, ul jani diximus, est ad quadi'aluiii recla* 



m. 



lit recla IIK ad reclain Kl; 



sed, ut recta HK ad rectani Kl, ita, siugulis in rectani KL duclis, 



rectaiip:iiliiin suli IIK in KL ad rectangiiluin siiIj IK in KL; 



rectanguluni vero sub HK in KL, ex natura paraboles Arcliiinedea*, 



*quatur (juadrato applicatœ HN, et rectanguluni sub IK in KL a-quatur 



(juadrato rect;e KL, qiiuni rectœ [K, KL facla' Ciiciinl a'(|uaies. Eril 



ii.'itur 



ul i|uailiMluiii UN ad qiuiilr;if uni KL, 



il;i qiuidialiiin laniieiilis Z\' ail qinidialuin recla' III. 



