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    <title>MaplePrimes - answers and comments on Question, Variation to the Helmholtz equation???</title>
    <link>http://www.mapleprimes.com/questions/99091-Variation-To-The-Helmholtz-Equation</link>
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    <lastBuildDate>Fri, 12 Jun 2026 09:33:33 GMT</lastBuildDate>
    <pubDate>Fri, 12 Jun 2026 09:33:33 GMT</pubDate>
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    <itunes:summary />
    <description>The latest answers and comments added to the Question, Variation to the Helmholtz equation???</description>
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      <title>MaplePrimes - answers and comments on Question, Variation to the Helmholtz equation???</title>
      <link>http://www.mapleprimes.com/questions/99091-Variation-To-The-Helmholtz-Equation</link>
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    <item>
      <title>pdsolve</title>
      <link>http://www.mapleprimes.com/questions/99091-Variation-To-The-Helmholtz-Equation?ref=Feed:MaplePrimes:Variation to the Helmholtz equation???:Comments#answer99095</link>
      <itunes:summary>&lt;p&gt;I tried it with pdsolve, but Maple couldn't solve it ina reasonable time (one try got a memory allocation error, another I stopped with Time 4954 seconds and Bytes 1.35G).&amp;nbsp; This could indicate a bug, or perhaps it's just a very complicated solution.&lt;br&gt;&lt;br&gt;with(VectorCalculus); SetCoordinates(cartesian[x,y,z]);&lt;br&gt;F:= VectorField(&amp;lt;f1(x,y,z),f2(x,y,z),f3(x,y,z)&amp;gt;);&lt;br&gt;eq:= Laplacian(F) + 2*b*c*Curl(F) + c*F;&lt;br&gt;pdsolve(convert(eq,set));&lt;/p&gt;
&lt;p&gt;However, you might look for solutions of the following form:&lt;/p&gt;
&lt;p&gt;F = &amp;lt;a1,a2,a3&amp;gt;*exp(k*x)&lt;/p&gt;
&lt;p&gt;(and those obtained by symmetry from that, and linear combinations...)&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;</itunes:summary>
      <description>&lt;p&gt;I tried it with pdsolve, but Maple couldn't solve it ina reasonable time (one try got a memory allocation error, another I stopped with Time 4954 seconds and Bytes 1.35G).&amp;nbsp; This could indicate a bug, or perhaps it's just a very complicated solution.&lt;br&gt;&lt;br&gt;with(VectorCalculus); SetCoordinates(cartesian[x,y,z]);&lt;br&gt;F:= VectorField(&amp;lt;f1(x,y,z),f2(x,y,z),f3(x,y,z)&amp;gt;);&lt;br&gt;eq:= Laplacian(F) + 2*b*c*Curl(F) + c*F;&lt;br&gt;pdsolve(convert(eq,set));&lt;/p&gt;
&lt;p&gt;However, you might look for solutions of the following form:&lt;/p&gt;
&lt;p&gt;F = &amp;lt;a1,a2,a3&amp;gt;*exp(k*x)&lt;/p&gt;
&lt;p&gt;(and those obtained by symmetry from that, and linear combinations...)&lt;/p&gt;
&lt;p&gt;&amp;nbsp;&lt;/p&gt;</description>
      <guid>99095</guid>
      <pubDate>Thu, 18 Nov 2010 13:30:17 Z</pubDate>
      <itunes:author>Robert Israel</itunes:author>
      <author>Robert Israel</author>
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    <item>
      <title>Functions of x</title>
      <link>http://www.mapleprimes.com/questions/99091-Variation-To-The-Helmholtz-Equation?ref=Feed:MaplePrimes:Variation to the Helmholtz equation???:Comments#answer99188</link>
      <itunes:summary>&lt;p&gt;Here are the solutions that are functions of x alone.&lt;/p&gt;
&lt;pre&gt;&amp;gt; with(VectorCalculus); SetCoordinates(cartesian[x,y,z]);&lt;br&gt;&amp;nbsp; F:= VectorField(&amp;lt;f1(x),f2(x),f3(x)&amp;gt;);&lt;br&gt;&amp;nbsp; eq:= Laplacian(F) + 2*b*c*Curl(F) + c*F;&lt;br&gt;&amp;nbsp; dsolve(convert(eq,set));&lt;/pre&gt;
&lt;p&gt;&lt;img class="math" src="http://www.mapleprimes.com/MapleImage.ashx?f=35933bb80b4cb8989c62aadc88235056.gif" alt="{f1(x) = _C5*sin(c^(1/2)*x)+_C6*cos(c^(1/2)*x), f2(x) = _C1*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C2*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C3*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)+_C4*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x), f3(x) = -1/2*(-4*b^2*_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c^2+4*b^2*_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c^2-4*b^2*_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c^2+4*b^2*_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c^2-_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(3/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(3/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)-_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(3/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)+_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(3/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)-_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c+_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c-_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c+_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c)/b/c^2}"&gt;&lt;/p&gt;</itunes:summary>
      <description>&lt;p&gt;Here are the solutions that are functions of x alone.&lt;/p&gt;
&lt;pre&gt;&amp;gt; with(VectorCalculus); SetCoordinates(cartesian[x,y,z]);&lt;br&gt;&amp;nbsp; F:= VectorField(&amp;lt;f1(x),f2(x),f3(x)&amp;gt;);&lt;br&gt;&amp;nbsp; eq:= Laplacian(F) + 2*b*c*Curl(F) + c*F;&lt;br&gt;&amp;nbsp; dsolve(convert(eq,set));&lt;/pre&gt;
&lt;p&gt;&lt;img class="math" src="http://www.mapleprimes.com/MapleImage.ashx?f=35933bb80b4cb8989c62aadc88235056.gif" alt="{f1(x) = _C5*sin(c^(1/2)*x)+_C6*cos(c^(1/2)*x), f2(x) = _C1*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C2*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C3*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)+_C4*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x), f3(x) = -1/2*(-4*b^2*_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c^2+4*b^2*_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c^2-4*b^2*_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c^2+4*b^2*_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c^2-_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(3/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)+_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(3/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)-_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(3/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)+_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(3/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)-_C1*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp(-(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c+_C2*(-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*exp((-c*(2*b^2*c+1+2*(b^2*c*(b^2*c+1))^(1/2)))^(1/2)*x)*c-_C3*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(-((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c+_C4*((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*exp(((-2*b^2*c-1+2*(b^2*c*(b^2*c+1))^(1/2))*c)^(1/2)*x)*c)/b/c^2}"&gt;&lt;/p&gt;</description>
      <guid>99188</guid>
      <pubDate>Sun, 21 Nov 2010 12:21:24 Z</pubDate>
      <itunes:author>Robert Israel</itunes:author>
      <author>Robert Israel</author>
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    <item>
      <title>Robert thanks, I am just getting back to this problem &amp; I think what you replied might help</title>
      <link>http://www.mapleprimes.com/questions/99091-Variation-To-The-Helmholtz-Equation?ref=Feed:MaplePrimes:Variation to the Helmholtz equation???:Comments#comment99959</link>
      <itunes:summary>&lt;p&gt;Robert thanks, I am just getting back to this problem &amp;amp; I think what you replied might help&lt;/p&gt;</itunes:summary>
      <description>&lt;p&gt;Robert thanks, I am just getting back to this problem &amp;amp; I think what you replied might help&lt;/p&gt;</description>
      <guid>99959</guid>
      <pubDate>Tue, 07 Dec 2010 21:29:21 Z</pubDate>
      <itunes:author>tsunamiBTP</itunes:author>
      <author>tsunamiBTP</author>
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