exercise-d-8.py

def f(m, mp, x, xp, xc, y, yp):
    h = x - xp
    return (m / (2 * h)) * (xc - xp) ** 2 - (mp / (2 * h)) * (x - xc) ** 2 + (y - m * h ** 2 / 6) / h - (
                yp - mp * h ** 2 / 6) / h


if __name__ == '__main__':
    matrix = [[1.410, 0.888551],
              [1.416, 0.889559],
              [1.422, 0.890637],
              [1.428, 0.891667],
              [1.434, 0.892687],
              [1.440, 0.893698]]

    xd_2 = (-2 * matrix[0][1] - 3 * matrix[1][1] + 6 * matrix[2][1] - matrix[3][1]) / (6 * 0.006)
    print(f'{xd_2=}')

    xdd_2 = (-2 * matrix[1][1] + 5 * matrix[2][1] - 4 * matrix[3][1] + matrix[4][1]) / 0.006 ** 2
    print(f'{xdd_2=}')

    sdd = -0.08823529411800789 * ((1.4258 - 1.422) / (1.428 - 1.422)) + -0.0980392156858277 * (
            (1.4528 - 1.428) / (1.422 - 1.428))
    print(f'{sdd=}')

    sd = f(
        -0.08823529411800789,
        -0.0980392156858277,
        1.428,
        1.422,
        1.4528,
        0.891667,
        0.890637
    )
    print(f'{sd=}')