( ) 
Hoc vero fioguHs hifcc curvis facillim^ applicator , fi 
indices p 8c q fecundum unius cujufque naturam ac ge- 
nium debito modo exponantur. 
Supponetur tertio Curvam tffe Ellipfiu^ujus 1 Axis 
Mador A K; ex cujus etiam equationc confequitur 
2yy=rx— xrxx. Unde provenit 
• • • • 
tx — 2rxx-- 2nx-i*2^xx = o, &: 
n=:r-j-x — rx, ac ptopterca i — r x fiibnormali D L 
2 q 2 q^ 
equalis. Sivero elBpfeos loco fubftitueretur Circulus^ 
equationem eodem modotraiSando, inveniemus DL = 
r — X, pofito r Circuli Radio asquali. 
Sed ad Ellipiiu revertendum , cujus alia proprietas 
cx hoc fonte deducenda eft, prout in. Parabola fadlum. 
Sit B D = f , unde A B =?^x — f Habemus L E *C =s 
LB9 -l-Efi^ ) =ri— rrx + rr XX + f f+rx- 
4. q qq 
rxx— rf f: &FL9(==4FDq4.L D9)==:rx--rxx-}- rr 
q q q 4 
^ttx 4- rr^xx: ErgOj^Lia — LF9 ssff— rff j 
q qq q 
Hisc ver6 eft TfteoR 6. Lib. 7. Conic de La Hire. 
Poftulat enim Geometra ille fnblimiS f ut lit n 
q — x:; L D> cujjus valor eft r — rx prout (upra in* 
vtntum ; 
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