%  define the function f
%  define the derivative df
%  define initial iterate x 
%  in advance
R = zeros(10,5);
for k=1:10
R(k,1) = k;
R(k,2) = x;  
R(k,3) = f(x);  R(k,4) = df(x);
R(k,5) = -R(k,3)/R(k,4);
x = x + R(k,5);
end