code: def aps02_f(x):
      r"""poles at x=n**2, 1st and 2nd derivatives at root are also close to 0"""
      ii = np.arange(1, 21)
      return -2 * np.sum((2 * ii - 5) ** 2 / (x - ii**2) ** 3)
  
imports: from random import random
  import numpy
  from scipy.optimize import zeros
label_desc: Use image node_id 16 for calling a global function with example usage: aps02_f(x) and returns: unknown