title: Standard deviation of one element
body: <p>When I try to execute</p>
  
  <pre><code>StandardDeviation[{1}]
  </code></pre>
  
  <p>I get an error</p>
  
  <pre><code>StandardDeviation::shlen: "The argument {1} should have at least two elements"
  </code></pre>
  
  <p>But std of one element is 0, isn't it?</p>