input: Write a function to correct the provided Python code for the given task by defining f1 properly and ensuring f2 returns the correct value.
  
  def f1(x):
      return x + 1
  
  def f2(x):
      return f1(x) * f1(x)
  
  print(f2(2)) #Output: 9
output: def f1(x):
      return x + 1
  
  def f2(x):
      return f1(x) * f1(x)