Barrow, Isaac
,
Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur
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ſit rectus, erit curva SEE _Ciſſois vulgaris_, ſeu _Dioslea_; </
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<
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alterius generis _Ciſſoidalis_. </
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<
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<
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<
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<
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. X.</
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<
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">Fig. 104.</
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ta, ut ductâ quâcunque EF ad poſitione datam AB parallelâ (quæ
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curvam AFG ſecet in E, curvámque AFI in F (ſit perpetim EF
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æqualis curvæ AEG ab A intercepto arcui AE; </
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<
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ET curvam AEG in E, ſitque ET æqualis arcui AE, & </
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tur recta TF; </
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s
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">Nam ducatur ntcunque recta GK ad AB parallela, lineas propo-
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ſitas ſecans, ut cernis; </
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&</
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<
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">unde punctum K extra curvam AFI
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VII.</
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tum eſt; </
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eandem habeat, nihilo ſeciùs recta FT curvam AFI tanget; </
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hac, & </
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cior aliquanto videtur, & </
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commodatior.</
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<
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item alia curva AIF talis, ut à D projectâ rectâ quâ cunque DEF,
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ſit ſemper intercepta EF par arcui AE; </
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AGE; </
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(è D) rectâ DK (quæ curvam TKF ſecet in K, rectámque TE in </
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