question is about : determine the highest real root of `f(X)= 2x^3 - 11.7x^2 +17.7x -5 `

with fixed – point iteration method (three iteration, x0 = 3)

i tried with python code :

import numpy as np x= 1 for i in range(3): x = 2*(x**3)-11.7*(x**2)+17.7*(x)-5 print(i,x)

the answer when i run this code is not right. what is wrong with my code? thanks.

## Answer

For the fixed-point iteration method you need to convert your original function `f(x)`

into an expression of the form `x = g(x)`

. Then iterate using the latter.

This is easy for a polynomial. In your case:

x = -(2 * x**3 - 11.7 * x**2 - 5) / 17.7