(1)椭圆方程为:x^2/(4m^2)+y^2/(3m^2)=1
(2)先写出FQ的方程:y=k(x+m)
它与y轴交于点M(0,km)
Q点坐标为:(-2m,-mk)
Q点落在椭圆上
1+k^2/3=1
k=0