format long
xu=2;
xl=0.5;
tolerance=0.0001;
err=1;
xr=(xu+xl)/2;
while (err > tolerance)
fxl=xl^3+4*xl^2-10;
fxr=xr^3+4*xr^2-10;
if (fxl*fxr<0)
	%root in lower interval
	%change upper limit
	xu=xr;
else
	%root in upper interval
	%change lower limit
	xl=xr;
end
oldxr=xr;
xr=(xu+xl)/2
err=abs((xr-oldxr)/xr)*100
end
root=xr