title: Cubic root of the negative number on python
body: <p>Can someone help me to find a solution on how to calculate a cubic root of the negative number using python?</p>
  
  <pre><code>&gt;&gt;&gt; math.pow(-3, float(1)/3)
  nan
  </code></pre>
  
  <p>it does not work. Cubic root of the negative number is negative number. Any solutions?</p>