('3) 



qiiae acqii.itio qiiidcrrj eft fcpnrata, cius aiitcm intcgratlo non 

 ftatim in ociilos inciin it , ciim tamcn ex rci natura facile in- 

 tclligatur, omncs has Traicdorias fcmper cfTc circulos. 



§. 17. Euoluamus primo cafum quo angulus intcr- 

 (cclionis cft rcdus, ("cu i^ zz: 00 , fictquc 



i a J f ^t it 



"o" a f — / / 77 »(» — ti ' 



cuius intcgralc eft 



liincquc ad numcros rcgrcdicndo fit tf — Z» / '-ipL , ita vt fit 

 a — ^ / - °~' , vndc , ohjz=:V(2.ax — xx)y fiet 

 ax=zlfV(^2ax — Jfjir) — bj. 



Sicquc tantum opus cft, vt loco a cius valor cx acquatione pro- 

 pofita fubilituatur, qui cft a — 2-I±JL£., hincque prodit j'/-+-jf* 

 — zby^ quac acquatio manifcfto cll pro infinitis circulis, fiquidem 

 parameter ^, qui ell radius horum circulorum, tanquam variabilis 

 fpedetur. Atque hi circuli omnes axcm in iplb pun6o A 

 tangent. 



§. 18- Pro angulis autem obllquis ncgotium facillime 

 cxpcdictur, ftatucndo -1=:^ zii 1; -y, ita vt fit /~ — i — , ideoquc 

 df— — *"^''^- ^ atque 1/(2/ — /;)r=:-^:L_ quibus valori- 



bus fubftitutis aequatio induet hanc formam : if — - -li^L. , 



1 — V y 



cuius intcgrale manifefto eft 



/fl — /(i — 5u)H-/A, fiue a=:b(i — 5c). 

 Cum igitur fit v — i/ izil — V '""^ , crit 



a=zb(i — J/ii--^); 



£ 3 qaflc 



