eps = 0.000001;
i=64;
x0=4;
x1=x0-1;
f0=x0^3-2*x0^2-11*x0+12;
while abs(x1-x0)>eps && i>1 && abs(x0^3-2*x0^2-11*x0+12) >eps,
    f1=diff(x0^3-2*x0^2-11*x0+12);
    x1=x0;
    x0=x0-(x0^3-2*x0^2-11*x0+12)/(3*x0^2-4*x0-11);
    i=i-1;

end
x0