function r = root_find2( n, a, b )

format compact
format long
xl = a;
xr = b;

for i=1:n
    
    xm = (xl + xr)/2;
    
    if ( xl^2 - 2 )*( xm^2 - 2 ) < 0
        xr = xm;
    else
        xl = xm;
    end
    r = xm;
end