f(-x)=(-x+m)/(x^2-nx+1)-f(x)=(-x-m)/(x^2+nx+1)f(-x)=-f(x)(-x+m)/(x^2-nx+1)=(-x-m)/(x^2+nx+1)(x-m)(x^2+nx+1)=(x+m)/(x^2-nx+1)(n-m)x^2-2m=0 无论x取何值均成立所以n-m=0 m=0n=m=0
