Jntcr dinantinm foci a ccntro et fcmiaxcm maiorem or- 

 bitae, ideoquc f\ fcmiaxis maior vnitate dcfignctur, cxccn- 

 tricitas ipfam didantiam foci a ccntro cxprimct. Rctentis 

 igitur ii!«dcm dcnominationibus ac in rroblcmate pracce» 

 dcnti, habebimus 



f ( I -h f cof. $) =r f' ( I 4- <• cof. 4:') , hinc 



c' — c— e{cco(.<p— c' cof. $' ) . 

 Statuamns nunc efle <P'-\-(^—z£ ct Cp' — (J) — 2 5, idco- 

 que Cp' — £ -+- 5 ct (p— e — <^, cric 



cof Cp) := cof. e cof 5 + fin. e fin. 5 et 



cof (^' — cof e cof 5 — fin. e fin. 5 , proinde 

 c^ — c- e (^{c — c^ ) cof e cof + ( t' + r) fin. e fin. 5), 

 Tnde colligitur 



'- — - cof e cof -h '^' fin. e fin. J. 

 Ponamus itaque ^']^-^ tang. 5 zr tang. ■>] , fietque 



e"«rff " ~" ^^^' ^ "^ ^'"" ^ ^'^"S- '/ 5 hincquc 



~^^ — — cof. e cof y\+ fin, e fin. V) — — cof (e + V]), 



cuius acquationis fubfidio inucnictur anguhis e H- 7/ , hinc- 

 qnc cognito iam angulo >] dctcrminabitur e , idcoquc 

 <J> — E - 5 ct Cp' zr £ 4- <J , tum vcro erit 



b — c [1 -\- e coi. (^) — c' [i 4- f cof Cp'}. 



§. 8. Tum hac quoque rationc ncgotium pcrfici 

 potcft: (ib 



Cp' r^ 2 4- (p, crit cof (f ' zz cof 2 5 cof Cp - fin. 2 cl fin. Cj), 



bincquc 



t' - ^z: r [ f cof 4^ — <:'cof 2 cof $-h<:'fin. 2 ^ fin. (J)), 



quac- 



