将m代入方程得m^2-2008m+1=0 得m^2+1=2008m
2m^2-4015m+2008/(m^2+1)-2=2m^2-4016m+2+m-4+2008/(m^2+1)
=2(m^2-2008m+1)+m-4+2008/2008m =m+1/m-4