function [k,X]=Newton(y,x0)
format long
syms x
m=zeros(1,100);
for i=1:100
    s=x0-subs(y,x,x0)/subs(diff(y),x,x0);
    if abs(s-x0)>1e-8
        x0=s;
        m(i)=x0;
    else
        m(i)=s;
        break
    end
end
k=i;
X=m(1,1:i);

結果顯示：

> [k,X]=Newton(x-log(x)-2,3)

k =

     4


X =

   3.147918433002165
 
   3.146193440797909   3.146193220620586   3.146193220620582