code: def aps04_f(x, n, a):
      r"""Medium-degree polynomial"""
      return x**n - a
  
imports: from __future__ import division, print_function, absolute_import
  from random import random
  import numpy
  from scipy.optimize import zeros
label_desc: Use image node_id 22 for calling a global function with example usage: aps04_f(x, n, a) and returns: unknown