title: unsupported operand type(s) for *: 'float' and 'builtin_function_or_method'
body: <pre><code>import numpy as np
  import math
  
  y = 0.
  m = 9.
  A = 0.3
  k = 4.
  gamma = 0.15
  t = 0
  
  n = 101
  
  t_array = np.zeros(n)
  y_array = np.zeros(n)
  dt = 25/n
  for i in range(n):
      t_array[i] = 0 + dt * i
      y_array[i] = A * math.exp(-gamma * t) * math.cos * (math.sqrt(k/m) * t)
      print("%5.2f %5.2f" % (y_array[i], t_array[i]))
  </code></pre>
  
  <p>I cannot for the love of my life figure out why I get the message: "unsupported operand type(s) for *: 'float' and 'builtin_function_or_method'". I've looked at pretty much all the suggestions on this website. Please help!</p>