import numpy as np

def f(x):
    return  (x**2)*(np.sin(x - 2)) - 4*x


def dfdx(x, h):
    return (f(x + h) - f(x - h))/(2*h)


val = 0.00001
x_n = 8
h = 0.0001

while abs(f(x_n)) > val:
    x_s = x_n
    print('x_s = ', x_s)

    x_np1 = x_n - f(x_n)/dfdx(x_n, h)
    x_n = x_np1