q = b*b-4*a*c
if a != 0:
  if q >= 0:
    w = math.sqrt(q)
    x1 = (-b + w) / 2*a
    x2 = (-b - w) / 2*a
    return x1, x2
  else:
    print('无实根')
else:
  x = -c/b
  return x