format long
xi=2;
xi1=1.8;
tolerance=1e-5;
err=1;
while (err>tolerance)
fxi=xi^3+4*xi^2-10;
fxi1=xi1^3+4*xi1^2-10;
slope=(fxi-fxi1)/(xi-xi1);

xr=xi1-fxi1/slope;
err=abs((xr-xi1)/xr)*100;
xi=xi1;
xi1=xr
end
root=xr