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

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4. gt;_ c_; in tertio, ſi _n_3
&
gt; _cc_√{_cc_/3} - {_cc_/3} √ {_cc_/3} = {2/3}_cc_ √ {_cc_/3}; vel _n_6& gt; {@@/27}_c_6; in quar-
to ſi _n_4&
gt; {_c_4/4} - {_c_4/16} = {3/16}_c_4;
5.
6. Curva CYH eſt _Circuli quadrans_, reliquæ AMH, ANH
quodammodo κυχλο{ει}δ{ετ}ς.
7. Ad ſextam ſeriem pertinentium curva HLL eſt _byperbola æqui_-
_latera_, cujus axis AH;
reliquæ ſunt _Hyperboliformes_. Unde quoad
hanc ſeriem liquent cætera.

_a_ + _b_ + {_cc_/_a_} = _n_.
_aa_ + _ba_ + _cc_ = _nn._
_a_3 + _baa_ + _cca_ = _n_3.
_a_4 + _ba_3 + _ccaa_ = _n_4, & c.
In recta BAH indefinitè protensâ capiatur AB = _b_; & in AD
Fig. 214.ad BH perpendiculari ſit AC = _c_;
ſint etiam anguli HAR, HBS Semi-
recti;
tum arbitrariè ductâ GY ad AH perpendiculari quæ ipſam
BS ſecet in Y;
fiat AG. AC: : AC. YK; & per K intra angulum
DVS deſcribatur _hyperbola_ KKK;
ſint demum curvæ CLL, AMM,
ANN tales, ut inter AG (vel GZ) &
GK ſit _media_ GL, _bime_-
_dia_ GM, _trimedia_ GN;
ſatisfacient negotio. Nam eſt GK = _a_
+ _b_ + {_cc_/_a_};
& GLq = _aa_ + _ba_ + _cc_; & GMcub = _a_3 + _baa_
+ _cca_;
& GNqq = _a_4 + _ba_3 + _ccaa_.

Not.

1. Secundi gradûs curva CLL eſt pars _hyperbolæ æquilateræ_, cujus
_centrum_ O, ipſam AB biſecans;
& gt; AO, eſt OH
(ad AB perpendicularis, &)
= √ ACq - AO qejus _ſemiaxis_;
lt; AO, ejus axis eſt OI = √ AOq - ACq. reliquæ
verò curvæ AMM, ANN ſunt _hyperboliformes_.