nonlinear

x = 1
e = 0.01
n = 100

def f(x):
        return (1/2)*((x-1)**3)-2*(x-1)

# def df(x,ea):
#         h = 0.5
#         return (f(x + h * ea) - f(x - h * ea)) / ea

def df(x):
        return 3/2*((x-1)**2) - 2

def rozw(r,ea,iter):
        for k in range (0,iter):
                r0 = r
                r = r - f(r) / df(r)#df(r,ea)
                er = abs((r-r0)/r)*100
                print(f"\n\n{r}    {er}\n\n")
                if er < ea:
                       break
        return r,er,k

x0,err,k = rozw(x,e,n)
print(f'x = {x}\n x0 = {x0}\nerr = {err}\nk = {k}')