title: ValueError: negative number cannot be raised to a fractional power
body: <p>When I tried this in terminal</p>
  
  <pre><code>&gt;&gt;&gt; (-3.66/26.32)**0.2
  </code></pre>
  
  <p>I got the following error</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ValueError: negative number cannot be raised to a fractional power
  </code></pre>
  
  <p>However, I am able to do this in two steps like,</p>
  
  <pre><code>&gt;&gt;&gt; (-3.66/26.32)
  -0.13905775075987842
  &gt;&gt;&gt; -0.13905775075987842 ** 0.2
  -0.6739676327771593
  </code></pre>
  
  <p>Why this behaviour? What is the way to solve this in single line?</p>