Barrow, Isaac
,
Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur
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rùm ex jam modò oſtenſis GT curvam DOG tangit; </
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<
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ſam DKE continget.</
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<
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xml:space
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<
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<
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<
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</
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<
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<
s
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xml:space
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<
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xml:space
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<
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xml:space
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<
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xml:space
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<
s
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xml:space
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DT. </
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<
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xml:space
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<
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<
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xml:space
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<
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</
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<
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xml:space
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<
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xml:space
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<
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<
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</
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<
s
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xml:space
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">Hæc autem perinde vera ſunt, nec abſimili modo demonſtrantur;
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</
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<
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<
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">pares ſint (quo ca-
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ſu curva AGEZ _Circulus_ erit, & </
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">_Curva_ DKE _Spiralis Archimedæa_)
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aut à DA continuò creſcant.</
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<
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xml:space
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<
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<
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ſignato in curva DKE puncto D ductis rectis DA, DG (quarum
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hæc ipſam DKE ſecetin K) ſit ſemper _Quadratum_ ex DK _Quadru-_
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<
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_plum ſpatii_ ADG; </
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<
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</
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xml:space
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<
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<
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pendicularis.</
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<
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xml:space
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">Nam concipiatur linea DOKO, per K tranſiens, naturâque talis
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ut ad illam à D projectæ (ceu DK) ſe habeant in eadem quâ ſpatia ADG
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ratione (quales lineas attigimus in proximè ſuperiori) & </
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DOK tangat recta KT, lineam DKE recta KS; </
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tem hæ cum ipſa HD punctis T, S; </
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</
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<
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xml:space
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<
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<
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niam è mox præmonſtratis DS = 2 DT) DH. </
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<
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<
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:</
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<
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xml:space
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larem eſſe: </
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<
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</
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<
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t
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unque defuncti ſumus. </
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nectemus à nobis uſitatum methodum ex Calculo tangentes reperien-
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di. </
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tritas methodos, an id ex uſu ſit facere. </
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<
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ſilio; </
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ſa videtur, ac generalis. </
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<
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ſitam curvam ſecet in M) & </
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