Huygens, Christiaan, Christiani Hugenii opera varia; Bd. 2: Opera geometrica. Opera astronomica. Varia de optica

Page concordance

< >
Scan Original
101 383
102 384
103 385
104 386
105
106 386
107
108 387
109
110 389
111 390
112 391
113 392
114 393
115 394
116 395
117 396
118 397
119 398
120
121
122
123 399
124 400
125 401
126 402
127 403
128 404
129
130
< >
page |< < (500) of 568 > >|
    <echo version="1.0RC">
      <text xml:lang="la" type="free">
        <div xml:id="echoid-div253" type="section" level="1" n="124">
          <pb o="500" file="0222" n="233" rhead="CHRIST. HUGENII"/>
          <p>
            <s xml:id="echoid-s4785" xml:space="preserve">In curvâ propoſita cujus æquatio x
              <emph style="super">3</emph>
            + y
              <emph style="super">3</emph>
            - axy = 0,
              <lb/>
            fiet ſecundum hanc regulam dividenda quantitas 3y
              <emph style="super">3</emph>
            - axy,
              <lb/>
            diviſor verò 3xx - ay; </s>
            <s xml:id="echoid-s4786" xml:space="preserve">ideoque z = {3y
              <emph style="super">3</emph>
            - axy/3xx - ay}, quæ
              <lb/>
            eſt longitudo cognita, cum dentur x, y & </s>
            <s xml:id="echoid-s4787" xml:space="preserve">a.</s>
            <s xml:id="echoid-s4788" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s4789" xml:space="preserve">Eſto item alia curva A B H, cujus æquatio axx - x
              <emph style="super">3</emph>
            -
              <lb/>
              <note position="left" xlink:label="note-0222-01" xlink:href="note-0222-01a" xml:space="preserve">TAB. XLV.
                <lb/>
              fig. 3.</note>
            qqy = 0, poſito ſcilicet a & </s>
            <s xml:id="echoid-s4790" xml:space="preserve">q eſſe lineas datas, A F vero
              <lb/>
            = x, F B = y. </s>
            <s xml:id="echoid-s4791" xml:space="preserve">Sit B E tangens, & </s>
            <s xml:id="echoid-s4792" xml:space="preserve">F E dicatur ut ante,
              <lb/>
            z. </s>
            <s xml:id="echoid-s4793" xml:space="preserve">Hîc fiet ſecundum regulam, dividenda quantitas - qqy;
              <lb/>
            </s>
            <s xml:id="echoid-s4794" xml:space="preserve">diviſor autem 2ax - 3xx; </s>
            <s xml:id="echoid-s4795" xml:space="preserve">unde z = {- qqy/2ax - 3xx} Ubi cum
              <lb/>
            dividenda quantitas ſit negata, ſi fuerit etiam diviſor minor
              <lb/>
            nihilo, hoc eſt ſi 2a minor quam 3x, erit z ſive fe ſumen-
              <lb/>
            da in partem ab A averſam. </s>
            <s xml:id="echoid-s4796" xml:space="preserve">Si vero 2a major quam 3x, ſu-
              <lb/>
            menda erit F E verſus A, ex præcepto regulæ.</s>
            <s xml:id="echoid-s4797" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s4798" xml:space="preserve">Horum vero rationem, ipſiuſque regulæ & </s>
            <s xml:id="echoid-s4799" xml:space="preserve">compendii quò
              <lb/>
              <note position="left" xlink:label="note-0222-02" xlink:href="note-0222-02a" xml:space="preserve">TAB. XLV.
                <lb/>
              fig. 4.</note>
            reducta eſt, originem ut explicemus, proponatur ut ante
              <lb/>
            curva B C, ad cujus punctum B tangens ducenda ſit.</s>
            <s xml:id="echoid-s4800" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s4801" xml:space="preserve">Intelligatur primum recta E B D, quæ non tangat curvam
              <lb/>
            ſed eam ſecet in B, atque item in alio puncto D, ipſi B
              <lb/>
            proximo; </s>
            <s xml:id="echoid-s4802" xml:space="preserve">rectæ autem A G occurrat in E; </s>
            <s xml:id="echoid-s4803" xml:space="preserve">& </s>
            <s xml:id="echoid-s4804" xml:space="preserve">ab utriſque
              <lb/>
            punctis B, D ducantur ad rectam A G, iiſdem angulis in-
              <lb/>
            clinatæ B F, D G; </s>
            <s xml:id="echoid-s4805" xml:space="preserve">& </s>
            <s xml:id="echoid-s4806" xml:space="preserve">ſit A F = x, F B = y, ſicut antea;
              <lb/>
            </s>
            <s xml:id="echoid-s4807" xml:space="preserve">ponatur que etiam F G data eſſe, quæ ſit e, quæraturque F E
              <lb/>
            = z.</s>
            <s xml:id="echoid-s4808" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s4809" xml:space="preserve">Eſt itaque ſicut E F ad F B, hoc eſt, ſicut z ad y, ita E G,
              <lb/>
            hoc eſt, z + e ad G D; </s>
            <s xml:id="echoid-s4810" xml:space="preserve">quæ erit y + {ey/z}; </s>
            <s xml:id="echoid-s4811" xml:space="preserve">& </s>
            <s xml:id="echoid-s4812" xml:space="preserve">hoc quidem
              <lb/>
            in qualibet curva ita ſe habere manifeſtum eſt.</s>
            <s xml:id="echoid-s4813" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s4814" xml:space="preserve">Nunc porrò conſideretur æquatio naturam curvæ conti-
              <lb/>
            nens, ex. </s>
            <s xml:id="echoid-s4815" xml:space="preserve">gr. </s>
            <s xml:id="echoid-s4816" xml:space="preserve">illa ſuperius propoſita x
              <emph style="super">3</emph>
            + y
              <emph style="super">3</emph>
            - xya = 0,
              <lb/>
            ubi a rectam longitudine datam, velut A H ſignificabat; </s>
            <s xml:id="echoid-s4817" xml:space="preserve">& </s>
            <s xml:id="echoid-s4818" xml:space="preserve">
              <lb/>
            patet, cum punctum D in curva ponatur, debere eodem mo-
              <lb/>
            do duas A G, G D, hoc eſt x + e & </s>
            <s xml:id="echoid-s4819" xml:space="preserve">y + {ey/z} ad ſe mutuo </s>
          </p>
        </div>
      </text>
    </echo>