e=c/a=1/2
c=a/2
b^2=a^2-c^2=a^2-a^2/4=3a^2/4
x^2/a^2+y^2/b^2=1
x^2/a^2+4y^2/3a^2=1
把(1,3/2)代人得：
1/a^2+3/a^2=1
a^2=4
b^2=3a^2/4=3
椭圆方程：x^2/4+y^2/3=1