f=@(x)exp(-x)-x;
df=@(x)-exp(-x)-1;
root=fzero(f,0.6);
% N-R method
x(1)=1;
x(2)=x(1)-f(x(1))/df(x(1));
err_app(1)=1;
err_app(2)=abs((x(2)-x(1))/x(2));
i=2;
while err_app(i)>=eps
    i=i+1;
    x(i)=x(i-1)-f(x(i-1))/df(x(i-1));
    err_app(i)=abs((x(i)-x(i-1))/x(i));
end
iteration=[1:1:i];
plot(iteration, err_app);