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# Title: Qua Continentur De Angulo Contactus & Semicirculi, Disquisitio Geometrica. De Sectionibus Conicis Tractatus. Arithmetica Infinitorum: sive de Curvilineorum quadraturâ, &c. Eclipseos Solaris Observatio (shelfmark Leibn. Marg. 84:2)
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De Sectionibus Conicis.
PROP. 30.
eltg 5. 8: : f. + 4. f =. 1 e - D E ejila; quadracum l’+a + 2fa 
DT9.
Tum (oropter Tansenrem) DTg = BOg (nempe aequalia,
sD E puneca coincidanes vel E lecus, illad majus,) hoc ctt,
+2  efa.  1d- a a2 +1a F 2da
1d - 42
plicando per-
1d 
eF. et (verinqs mulci
S2) eric pe cd s a +Ida = d a  t 2fida  +
25d2 a =s 1d - f= d  f2 a + f 1a  257da. EF C delecis u
erinqi perdm s a, acg; dividendo per a) eric L ida Fd 
2sid =2f42= Fs at s in  25 d.
Denigs, ponendo D F idem esse punctum, CuE erane(cab
quancicas a - P. D, ade0g; e iplius mulciplicia ida, d a, f a eric
2s1d in 3fd = s=1 n 25 d. Ec (diridendo per 25) id - d-
Esi  fd. (Hoc eAt, HAFA =-DCEF) vel =I nd. 1Ld:: d f. HOC
est, C.Co Ba:: EA. EF. vel (alcernanco) EC FA :: La, EF. 110d
erac inquirendum.
Duod Theoremasic inventum hoc est. Si st Ordina-
tim applicata in elliph E, aeq ab applicationis pun-
eto F ellipleos diameter per propiorem rerticem A
continuetur ad F; Citq3, ut distantia puncti applica-
tionis a Centro B.C, ad diametrum incerceptam P A,
sic reliduum transversae diametriea, ad diamerrum
interceptam continuatam EP: recta at Elliplm in
DUMCTO a CONTINSCE.
Demonstratio (s Opus) insticui poteric repecicis Analy (eos
rettisiis.
Sed _ hinc concludi pocek quod modo aliunde ottensum e-
rac; nemDe quod Recta PIlipsin in diametri verrice contineens diame-
tro conjuearae parallela est eique nunguam occursura. NVAM, CUm ACFC.
LA:: La. F. F s Cpropter coincidenciam punctorum FC)
Prima P. C. nulla sie C sire nullius magnicudinis) quarca P V
vel CF) crit infinica (ex veraris parce lupponatur diameter
Produci, sire per A, Cire per 2, indifferencer enim se Pangens
haber