title: Why is sin(180) not zero when using python and numpy?
body: <p>Does anyone know why the below doesn't equal 0?</p>
  
  <pre><code>import numpy as np
  np.sin(np.radians(180))
  </code></pre>
  
  <p>or:</p>
  
  <pre><code>np.sin(np.pi)
  </code></pre>
  
  <p>When I enter it into python it gives me 1.22e-16.</p>