Barrow, Isaac, Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur

Table of contents

< >
[81. Not.]
[82. Not.]
[83. Series quarta.]
[84. Not.]
[85. Series quinta.]
[86. Series ſexta.]
[87. Not.]
[88. Series ſeptima.]
[89. Not.]
[90. Series octava.]
[91. Series nona.]
[92. Not.]
[93. Series decima.]
[94. Series undecima.]
[95. Not.]
[96. Series duodecima]
[97. Series decima tertia]
[98. Not.]
[99. Laus DEOO ptimo Maximo. FINIS.]
[100. ERRATA]
[101. Addenda Lectionibus Geometricis.]
[102. _Probl_. I.]
[103. _Probl_. II.]
[104. _Probl_. III.]
[105. Addenda Lectionibus Geometricis.]
[106. _Theor_. I.]
[107. _Theor_. II.]
[108. _Theor_. III.]
[109. _Theor_. IV.]
[110. _Theor_. V.]
< >
page |< < (63) of 393 > >|

Lect. IX.

I. Q Ualiter in obverſum Speculi circularis convexum finitè di-
ſtans punctum radiat, &
ubi loci adparet oculo in recta con-
ſtituto per ipſum radians &
ſpeculi centrum trajecta poſtremo con-
niſi demonſtrare;
nunc idem quoad aſpectum aliàs ubicunque ſitum
aggredimur expiſcari.
quò primum attinet ut rectam inveſtigemus,
in qua conſiſtet Imago;
tum ut punctum ejus in iſta recta præciſum
determinemus.
& primo quidem negotio ſatisfactum erit hujuſmodi
_Prob@ema_ conficiendo;
quod (ſequentium quoque gratiâ) genera-
tim proponimus.
II. _Dato circulo reflectente_ (cujus centrum C) _datiſque binis pun-_
_ctis;
ab horum uno recta ducatur, cujus rtflexus per alterum tran-_
_ſeat._
1. Si data puncta (puta A, X) ſint ambo in circuli peripheria,
Fig. 86.manifeſtum eſt biſecto arcu AX in N, connexiſque ſubtenſis NA,
N X, rectas NA, NX ſibi mutuò reflexas fore;
ſeu, junctâ CN,
angulum CNXangulo CNA æquari.
2. Etiam ſi datorum unum (X) in circumferentia ponatur; liquet,
Fig. 87.connexis AX, CX, factóque angulo CXH = CXA, ſore XA,
XH alterum alterius reflexum.
3. Item ſi data puncta (A, X) æqualiter à centro diſtent; con-
Fig. 83.nexis rectis AC, XC, biſectóque angulo XCA à recta CN circu-
lum reflectentem interſecante ad N;
perſpicuum eſt conjunctas rectas
AN, XN, invicem in ſe reflecti;
vel angulum CNXipſi CNA
æquari.
III. 4. Si puncta data (puta jam A, K) ambo exiſtant in recta per
reflectentis centrum tranſeunte (nempe AB KC.)
I. Fiat CK. AC: : CB. T. ac inter CB, & T ſit proportione
Fig. 8@.media V (unde CBq.
Vq: : CB. T: : CK. AC). tum centro A,
intervallo √:
: ACq - Vq. deſcribatur circulus reflectentem

Text layer

  • Dictionary

Text normalization

  • Original

Search


  • Exact
  • All forms
  • Fulltext index
  • Morphological index