for a in [1]:
  for c in [0.000001]:
    for b in range(1., 2000., 100.):
      if (b**2 - 4.*a*c):
        xn = (-b - sqrt(b**2 - 4.*a*c)) / (2.*a)
        xp1 = (-b + sqrt(b**2 - 4.*a*c)) / (2.*a)
        xp2 = (c/a) / xn
        print 'xn = ', xn, 'xp1 = ', xp1, 'xp2 = ', xp2, '(xp2 - xp1)/xp2 = ', (xp2 - xp1)/xp2