1.2m^2=3m-1,即m=1/2或m=1
x^2+y^2=2 或x^2+y^2=1/2
2.焦点在X轴,a^2=2m^2,b^2=3m-1
c^2=a^2-b^2=2m^2-(3m-1)=3
m=2或m=-1/2
m=-1/2,b^2=3m-1