text: from __future__ import division
  import numpy as np
  import matplotlib.pyplot as plt
  import thequickmath as qm
  
  x = np.linspace(-10, 10., num=1000, endpoint=True)
  func_1 = lambda h, x: h/x
  func_2 = lambda r, x: r/np.sqrt(1 + x**2)
  
  #for i in np.arange(-1, 1, 0.1):
  #    plt.plot(x, func_1(i, x))
  
  #for i in np.arange(0, 2, 0.1):
  #    plt.plot(x, func_2(i, x))
  
  #plt.plot(x, func_1(i, x))
  plt.plot(x, func_2(1, x))
  
  #plt.axis([0, 1, -0.2, 0.001])
  #plt.xlabel('$s$')
  #plt.ylabel('$f_k(1 - s Ma^{-\gamma})$')
  plt.show()