这题目我似乎见过,你是要求中点M的轨迹么.A(x1,y1);B(x2,y2);M(x0,y0)y=2x+m 代入 4x^2+9y^2=364x^2+9(2x+m)^2-36=040x^2+36xm+9m^2-36=01# △=36*36m^2-4*40*9(m^2-4)>0 9m^2-10m^2+40>0; m^2