title: No print output with functions
body: <p>I've created multiple functions that doesn't output the final number as the print, can anyone help please. Thanks.</p>
  <pre><code>strips = int(input('Enter your number of strips: '))
  lower = int(input('Enter your lower limit'))
  upper = int(input('Enter your upper limit'))
  
  #define Trapzeium rule
  def trapezium(function3,lower,upper,strips):
      h=float(upper-lower)/strips
      result=0.5*function3(lower)+0.5*function3(upper)
      for i in range(1,strips):
          result+=function3(lower+i*h)
      result=h*result
      return result
  
  #define function3
  def function3(x):
      return 3*(x**2)*exp(x**3)
      trapezium_numerical=trapezium(function3,lower,upper,strips)
      print(trapezium_numerical)
  </code></pre>