def discrete_forward_difference(f0, x0, f1, x1):
    """
    Compute numerical derivative of a scalar valued, univariate function f using two discrete point evaluations.

    :param float f0: Function value at x0.
    :param float x0: First point where the function has been evaluated.
    :param float f1: Function value at x1.
    :param float x1: Second point where the function has been evaluated.
    :return: Numerical approximation of the derivative.
    :rtype: float
    """
    return (f1 - f0) / (x1 - x0)