= (15^)== 



at ob u — u^ :rz V — v\ fit omnino 



fin. ^ (u — f/) — fin.l(v — v") et 



cof. l (u — u^) — cof. I (c; — '■/) , 

 vnde concluditur non Iblum 



e cof. l (u -f- w) = / cof. J (17 -f- 'v")i 

 verum etiam 



e cof. • (« — //) cof. i (k -I- «0 = 



f^ cof. 5 (-y — 'V) cof. ! (-y -H -y^) , ideoque 



^ ( cof. u H- cof. u") z=z e" ( cof. i; -h cof. -y^) , 

 vnde omnii o concluditur efle r -+- r^ = ^ -+- ^^ Deinde quia eft 



cof. ( Cp — CpO ==: cof. Cp cof. 0' -h fin. Cj) fin. (p)^ 



( co( •" — p 1 ( cjf. •"' — (* 1 -^- fin. fi fm. v' [ i — «>* ( . 



~~~~~ [ i — e coj. u ) i I — c co . u^ ) 



fi corda Ellipfis quae angulum Cp— Cj)^ fubtendit, dicatur /, ent 



j2 - ^^ ^ / ^ _ 2 r / cof (Cj) - Cfy) := (r -h r')' - 2 r / (i -1- cof. (Cp - Cp'))^ 



ideoque 



2rr"(i-+-cof(Cl)— CpO) = (^-^^)'— A 

 tumque pro altera Ellipfi, fi corda fubtendens angulum \{/— •v|>'' 

 dicatur cr, fiet 



2^^^(H-cof.(v|. — v|.0) = (?-F?0' — ^. 

 Atqui e(l 



rr^^rfl*^! — ^cof.«)(i — fcof.w^) et 



^=" — a'{i- — f^cof.T)^! — e^oLv")^ 



fiet igitur 



(i — ^cof.w) (i — ecof.i/) -i-(cof.« — e) (coCu"—e) -f- 



fin. ?< fin. // ( I — fM — ' " -^/ '' — £^,- et 



(i— ^''cof.a;) (i— f-^cof.i;'') -f-(cof.^'— f') (cof.-u''— /)-f- 

 fin.-yfm.-y^^i-^^M — '-^!!!— 2L. 



At- 



