郭敦顒回答:
椭圆C:x²/a²+y²/b²=1(a>b>0)过点p(2,1),离心率e= c/ a=(√3)/2
4/a²+1/b²=1 (1)
c =(√3)a/2 (2)
b2+c2=a2, (3)
(2)代入(3)得,b2+(3/4)a2=a2,b2=(1/4)a2 (4)
郭敦顒回答:
椭圆C:x²/a²+y²/b²=1(a>b>0)过点p(2,1),离心率e= c/ a=(√3)/2
4/a²+1/b²=1 (1)
c =(√3)a/2 (2)
b2+c2=a2, (3)
(2)代入(3)得,b2+(3/4)a2=a2,b2=(1/4)a2 (4)