Polyline_method

def polyline_method(rng, eps):
    l = lipshic_const(rng, eps)

    left = rng[0]
    right = rng[1]

    x = (1 / (2 * l)) * (f(left) - f(right) + l * (left + right))
    y = (1 / 2) * (f(left) + f(right) + l * (left - right))

    first_delta = (1 / (2 * l)) * (f(x) - y)
    second_delta = 2 * l * first_delta

    while second_delta > eps:
        first_x = x - first_delta
        second_x = x + first_delta

        if f(first_x) < f(second_x):
            x = first_x
        else:
            x = second_x

        f_val = 0.5 * (f(x) + y)
        first_delta = 1 / (2 * l) * (f(x) - y)
        second_delta = 2 * l * first_delta
        y = f_val

    return (x, f(x))

print(polyline_method([-3, 3], 0.001))