g=9.81; v=40; m=68.1; t=10;
%initial guesses
xL=12;
xU=17;
xR=(xL+xU)/2;
tolerance=0.00001;
err=1;
%bisecting loop
while (err>tolerance)
%bisecting
xRold=xR;

fL=v-(g*m/xL)*(1-exp(-g*xL*t/m));
fR=v-(g*m/xR)*(1-exp(-g*xR*t/m));

	if (fL*fR<0)
		xU=xR;
	else
		xL=xR;
	end
xR=(xL+xU)/2;
err=abs((xR-xRold)/xR)*100;
end
root=xR