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

Page concordance

< >
Scan Original
211 18
212 19
213 20
214 21
215 22
216 23
217 24
218 25
219 26
220 27
221 28
222 29
223 30
224 31
225 32
226 33
227 34
228 35
229 36
230 37
231 38
232 39
233 40
234 41
235 42
236 43
237 44
238 45
239 46
240 47
< >
page |< < (47) of 393 > >|
    <echo version="1.0RC">
      <text xml:lang="la" type="free">
        <div xml:id="echoid-div222" type="section" level="1" n="31">
          <p>
            <s xml:id="echoid-s9839" xml:space="preserve">
              <pb o="47" file="0225" n="240" rhead=""/>
            DE x HO ergò DH x BF + DH x KO = DE x HO; </s>
            <s xml:id="echoid-s9840" xml:space="preserve">hoc eſt
              <lb/>
            DH x BF + DH x HO - DH x BL = DE x HO; </s>
            <s xml:id="echoid-s9841" xml:space="preserve">tranſpo-
              <lb/>
            nendo igitur eſt DH x HO - DE x HO = DH x BL - DH x
              <lb/>
              <note position="right" xlink:label="note-0225-01" xlink:href="note-0225-01a" xml:space="preserve">Fig. 39.</note>
            BF. </s>
            <s xml:id="echoid-s9842" xml:space="preserve">hoc eſt EH x HO = DH x FL; </s>
            <s xml:id="echoid-s9843" xml:space="preserve">vel EH x GO + EH x
              <lb/>
            HG = DE x FL + EH x FL; </s>
            <s xml:id="echoid-s9844" xml:space="preserve">quare, demptis æqualibus, eſt EH
              <lb/>
            x GO = DE x FL; </s>
            <s xml:id="echoid-s9845" xml:space="preserve">vel ZG x GO = DE x FL; </s>
            <s xml:id="echoid-s9846" xml:space="preserve">cum itaque
              <lb/>
            DE x FL ſit quid determinatum, conſtat lineam OBO effe hy-
              <lb/>
            perbolam, cujus aſymptoti ZR, ZS.</s>
            <s xml:id="echoid-s9847" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9848" xml:space="preserve">V. </s>
            <s xml:id="echoid-s9849" xml:space="preserve">Si MO capiatur ad alteras rectæ BC partes, etiam DE.
              <lb/>
            </s>
            <s xml:id="echoid-s9850" xml:space="preserve">BF ad alteras punctorum D, B partes accipi debent; </s>
            <s xml:id="echoid-s9851" xml:space="preserve">uti Schema
              <lb/>
              <note position="right" xlink:label="note-0225-02" xlink:href="note-0225-02a" xml:space="preserve">Fig. 40.</note>
            monſtrat; </s>
            <s xml:id="echoid-s9852" xml:space="preserve">nec abludit modus demonſtrandi.</s>
            <s xml:id="echoid-s9853" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9854" xml:space="preserve">VI. </s>
            <s xml:id="echoid-s9855" xml:space="preserve">Conſectarium. </s>
            <s xml:id="echoid-s9856" xml:space="preserve">Si recta BQ angulum ABC ſecet, pér-
              <lb/>
            que punctum D ducantur utcunque duæ rectæ MN, XY rectam
              <lb/>
              <note position="right" xlink:label="note-0225-03" xlink:href="note-0225-03a" xml:space="preserve">Fig. 41.</note>
            BQ interſecantes punctis OP (quorum utique ſit O propius ip-
              <lb/>
            ſi B) erit MN. </s>
            <s xml:id="echoid-s9857" xml:space="preserve">MO &</s>
            <s xml:id="echoid-s9858" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9859" xml:space="preserve">XY. </s>
            <s xml:id="echoid-s9860" xml:space="preserve">XP. </s>
            <s xml:id="echoid-s9861" xml:space="preserve">Nam per O deſcripta con-
              <lb/>
            cipiatur _hyperbola_ VOB (qualem jam mox attigimus, ſic ut inter-
              <lb/>
            ceptæ rationem habeant illam quam MN ad MO) erit igitur
              <lb/>
            MN. </s>
            <s xml:id="echoid-s9862" xml:space="preserve">MO:</s>
            <s xml:id="echoid-s9863" xml:space="preserve">: (XY. </s>
            <s xml:id="echoid-s9864" xml:space="preserve">XV) &</s>
            <s xml:id="echoid-s9865" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9866" xml:space="preserve">XY. </s>
            <s xml:id="echoid-s9867" xml:space="preserve">XP.</s>
            <s xml:id="echoid-s9868" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9869" xml:space="preserve">_Coroll._ </s>
            <s xml:id="echoid-s9870" xml:space="preserve">Dividendo eſt NO. </s>
            <s xml:id="echoid-s9871" xml:space="preserve">MO &</s>
            <s xml:id="echoid-s9872" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9873" xml:space="preserve">YP. </s>
            <s xml:id="echoid-s9874" xml:space="preserve">PX.</s>
            <s xml:id="echoid-s9875" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9876" xml:space="preserve">VII. </s>
            <s xml:id="echoid-s9877" xml:space="preserve">Quinimò ſi plures lineæ BQ, BG angulum ABC ſecent;
              <lb/>
            </s>
            <s xml:id="echoid-s9878" xml:space="preserve">
              <note position="right" xlink:label="note-0225-04" xlink:href="note-0225-04a" xml:space="preserve">Fig. 42.</note>
            & </s>
            <s xml:id="echoid-s9879" xml:space="preserve">à puncto D projiciantur rectæ DN, DY (quæ rectas alteras
              <lb/>
            interſecant ut vides; </s>
            <s xml:id="echoid-s9880" xml:space="preserve">quarúmque DN puncto B vicinior;) </s>
            <s xml:id="echoid-s9881" xml:space="preserve">erit
              <lb/>
            NE. </s>
            <s xml:id="echoid-s9882" xml:space="preserve">MO &</s>
            <s xml:id="echoid-s9883" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9884" xml:space="preserve">YF. </s>
            <s xml:id="echoid-s9885" xml:space="preserve">VX.</s>
            <s xml:id="echoid-s9886" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9887" xml:space="preserve">Nam NE. </s>
            <s xml:id="echoid-s9888" xml:space="preserve">EO &</s>
            <s xml:id="echoid-s9889" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9890" xml:space="preserve">YF. </s>
            <s xml:id="echoid-s9891" xml:space="preserve">FV; </s>
            <s xml:id="echoid-s9892" xml:space="preserve">& </s>
            <s xml:id="echoid-s9893" xml:space="preserve">EO. </s>
            <s xml:id="echoid-s9894" xml:space="preserve">OM &</s>
            <s xml:id="echoid-s9895" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9896" xml:space="preserve">FV. </s>
            <s xml:id="echoid-s9897" xml:space="preserve">VX. </s>
            <s xml:id="echoid-s9898" xml:space="preserve">i-
              <lb/>
            gitur ex æquo eſt NE. </s>
            <s xml:id="echoid-s9899" xml:space="preserve">OM &</s>
            <s xml:id="echoid-s9900" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s9901" xml:space="preserve">YF. </s>
            <s xml:id="echoid-s9902" xml:space="preserve">VX.</s>
            <s xml:id="echoid-s9903" xml:space="preserve">‖</s>
          </p>
          <p>
            <s xml:id="echoid-s9904" xml:space="preserve">VIII. </s>
            <s xml:id="echoid-s9905" xml:space="preserve">Etiam exindè patet, per B (ad partes alterutras) rectam
              <lb/>
            duci poſſe; </s>
            <s xml:id="echoid-s9906" xml:space="preserve">ità ut è D eductarum partes ab illa rectáque BC ad
              <lb/>
            interceptas à rectis BA, BC rationem habeant minorem quâpi-
              <lb/>
            am datâ.</s>
            <s xml:id="echoid-s9907" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9908" xml:space="preserve">Nam ſumatur PQ = PZ; </s>
            <s xml:id="echoid-s9909" xml:space="preserve">ergò connexa BQ _hyperbolam_ O
              <lb/>
            BO tangit; </s>
            <s xml:id="echoid-s9910" xml:space="preserve">& </s>
            <s xml:id="echoid-s9911" xml:space="preserve">liquet à rectis BQ, BC interceptas ad intercep-
              <lb/>
            tas à BC, BA minorem rationem habere, quàm habent inter-
              <lb/>
            ceptæ ab hyperbolâ OBO & </s>
            <s xml:id="echoid-s9912" xml:space="preserve">recta BC ad eaſdem; </s>
            <s xml:id="echoid-s9913" xml:space="preserve">hoc eſt mi-
              <lb/>
            norem datâ quâpiam.</s>
            <s xml:id="echoid-s9914" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s9915" xml:space="preserve">IX. </s>
            <s xml:id="echoid-s9916" xml:space="preserve">Sit rurſum angulus rectilineus ABC, & </s>
            <s xml:id="echoid-s9917" xml:space="preserve">punctum D; </s>
            <s xml:id="echoid-s9918" xml:space="preserve">item
              <lb/>
              <note position="right" xlink:label="note-0225-05" xlink:href="note-0225-05a" xml:space="preserve">Fig. 43.</note>
            </s>
          </p>
        </div>
      </text>
    </echo>