title: Importing math and TypeError: 'builtin_function_or_method' object is not subscriptable
body: <pre><code>import math as m
  
  def get_distance(latx,lonx,latp,lonp):
      '''
      Calculate the angular distance from point, x, to pole, p.
      Inputs and outputs should be in radians.
      '''
      # YOUR CODE HERE
  
      angular_distance = m.cos[m.sin(latx)*m.sin(latp)+m.cos(latx)*m.cos(latp)*m.cos(lonp-lonx)]
      print(angular_distance)
      raise NotImplementedError()
  
  get_distance(48,50,87,22)
  </code></pre>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Users\13609\Documents\Search\dg.py", line 14, in &lt;module&gt;
      get_distance(48,50,87,22)
    File "C:\Users\13609\Documents\Search\dg.py", line 10, in get_distance
      angular_distance = m.cos[m.sin(latx)*m.sin(latp)+m.cos(latx)*m.cos(latp)*m.cos(lonp-lonx)]
  TypeError: 'builtin_function_or_method' object is not subscriptable
  
  </code></pre>