This is a mathematica code for fixed point iteration.
expr={1,0,9999};
f[{i_,xi_,err_}]:=(xipp=0.2062129*(20+(2*xi))^(2/5);
{i+1,xipp,Abs[(((xipp-xi)/(xipp))*100)]});
NestWhileList[f,expr,#[[3]]>=.05&]
If I were to prove this converges for all initial guesses would I use the same code and replace the function with its derivative?
