title: Solving two non-linear equations in Octave
body: <p>I am trying to solve the following two equations using Octave:</p>
  
  <pre><code>eqn1 = (wp/Cwc)^(2*N) - (1/10^(0.1*Ap))-1 == 0;
  eqn2 = (ws/Cwc)^(2*N) - (1/10^(0.1*As))-1 == 0;
  </code></pre>
  
  <p>I used the following code:</p>
  
  <pre><code>syms Cwc N
  eqn1 = (wp/Cwc)^(2*N) - (1/10^(0.1*Ap))-1 == 0;
  eqn2 = (ws/Cwc)^(2*N) - (1/10^(0.1*As))-1 == 0;
  sol = solve(eqn1 ,eqn2, Cwc, N)
  </code></pre>
  
  <p><code>ws</code>,<code>wp</code>,<code>As</code>, and <code>Ap</code> are given as <code>1.5708</code>, <code>0.31416</code>, <code>0.5</code>, <code>45</code> respectively.</p>
  
  <p>But I am getting the following error: </p>
  
  <blockquote>
    <p>error: Python exception: NotImplementedError: could not solve
    <br><code>126491*(pi*(3*10**N*sqrt(314311)*pi**(-N)/1223)**(1/N)/2)**(2*N) - 126495</code>
    <br>   occurred at line 7 of the Python code block:
    <br>   <code>d = sp.solve(eqs, *symbols, dict=True)</code></p>
  </blockquote>
  
  <p>What should I do to solve this?</p>
  
  <hr>
  
  <p><strong>Edit:</strong></p>
  
  <p>I modified the equations a little bit.</p>
  
  <pre><code>pkg load symbolic
  clear all
  syms Cwc N
  wp = 0.31416
  ws = 1.5708
  As = 45
  Ap = 0.5
  eqn2 = N - log10(((1/(10^(0.05*As)))^2)-1)/2*log10(ws/Cwc) == 0;
  eqn1 = N - log10(((1/(10^(0.05*Ap)))^2)-1)/2*log10(wp/Cwc) == 0;
  sol = solve(eqn1,eqn2,Cwc,N)
  </code></pre>
  
  <p>And now I am getting this error:</p>
  
  <blockquote>
    <p>error: Python exception: AttributeError: <code>MutableDenseMatrix</code> has no attribute <code>is_Relational</code>.
    <br>   occurred at line 3 of the Python code block:
    <br>  <code>if arg.is_Relational:</code></p>
  </blockquote>