title: Issue with Matlab solve function?
body: <p>The following command </p>
  
  <pre><code>syms x real;
  f = @(x) log(x^2)*exp(-1/(x^2));
  fp(x) = diff(f(x),x);
  fpp(x) = diff(fp(x),x);
  </code></pre>
  
  <p>and</p>
  
  <pre><code>solve(fpp(x)&gt;0,x,'Real',true)
  </code></pre>
  
  <p>return the result</p>
  
  <blockquote>
    <p>solve([0.0 &lt; (8.0*exp(-1.0/x^2))/x^4 - (2.0*exp(-1.0/x^2))/x^2 -
    (6.0*log(x^2)*exp(-1.0/x^2))/x^4 + (4.0*log(x^2)*exp(-1.0/x^2))/x^6],
    [x == RD_NINF..RD_INF])</p>
  </blockquote>
  
  <p>which is not what I expect.</p>
  
  <p>The first question: <b>Is it possible to force Matlab's <code>solve</code> to return the set of all solutions?</b></p>
  
  <p>(This is related to <a href="https://stackoverflow.com/questions/23811199/unexpected-result-on-solving-some-inequality-in-matlab-symbolic-computation">this question</a>.) Moreover, when I try to solve the equation</p>
  
  <pre><code>solve(fpp(x)==0,x,'Real',true)
  </code></pre>
  
  <p>which returns</p>
  
  <blockquote>
    <p>ans =<br>
    -1.5056100417680902125994180096313</p>
  </blockquote>
  
  <p>I am not satisfied since all solutions are not returned (they are approximately -1.5056, 1.5056, -0.5663 and 0.5663 obtained from WolframAlpha).</p>
  
  <p>I know that <code>vpasolve</code> with some initial guess can handle this. But, I have no idea <b>how I can generally find initial guessed values to obtain all solutions</b>, which is my second question.</p>
  
  <p>Other solutions or suggestions for solving these problems are welcomed.</p>