input: def poly_derivative(coeffs: list):
      """ coeffs are the coefficients of a polynomial function.
      coeffs[0] + coeffs[1] * x + coeffs[2] * x^2 + ....
      Returns the derivative of the polynomial with the same coefficient form.
      >>> poly_derivative([3, 1, 2, 4, 5])
      [1, 4, 12, 20]
      >>> poly_derivative([1, 2, 3])
      [2, 6]
      """
output:     
      derivative = []
      for i in range(1, len(coeffs)):
          derivative.append(i * coeffs[i])
      return derivative
  