input: Write a python function to find roots of a quadratic equation.
  assert findRoots(1, -3, 2) == (2.0, 1.0)
  assert findRoots(1, 2, 1) == (-1.0,)
  assert findRoots(1, 0, 1) == 'No real roots.'
output: def findRoots(a, b, c):
      import cmath
      discriminant = b**2 - 4*a*c
      if discriminant > 0:
          root1 = (-b + discriminant**0.5) / (2*a)
          root2 = (-b - discriminant**0.5) / (2*a)
          return (root1, root2)
      elif discriminant == 0:
          root = -b / (2*a)
          return (root,)
      else:
          return 'No real roots.'