99 

 ' t = tf-H? et „ = £-,)/. 

 At, ob g^K=,-^=v P t f^- --? + ^, erit 



1 d* ' 1 x'--f-îax' o* (îhi' + ï'»)» 



'a-+-x'1 3 y' (<* -h x') a y' , ■ 



r — ^Z-tii- , n = - - et m — -f===L= , hincque 

 t = x' 4- (x' -4- à) = 2 x 7 H- a sea x x — f -^^ et: 



u 





(f + 'j/q - a)Cf-f-3°) fl 7 f-J-«-j-V(f — q)(r-t- 3 g) / . x . 



unde patet longitudinem fili in vertice evolutae aequa- 

 lem esse quantitati a. 



Nunc, si in curva 2 probl. ponatur 6 — 2 a deturque 

 eidem talis positio, ut axem abscissaium spectet latere con- 

 vexo, abit aequatio pro eadem inventa, §. 12., insequenttm: 



x> xx— 40a — 4aaZ. - a — - - 



y = - — 



4 a 



Sin autem initium abscissaium appropinquet verticem ver- 

 sus quantitate a, quod evenit ponendo x / zzzx // -j~a, erit: 



(tf + fl) / x -a_ f . 2flX //~ 3fl 7__ 4fl a / ^« + /< ^^lg 

 /- ~ 



4 a 



(x" h- <Q Y (x" - a) (x" -hTo" ) , x" -h a 4- Y~ x" - a ) (x~+w) . 



quae aequatio perfecte congruit cum aequatione A. 



13* 



