(1)∵A(-a,0),B(0,b),∴直线AB的斜率kAB=
,b a
∵CF⊥x轴,∴将x=c代入椭圆方程得
=1?y2 b2
=c2 a2
,y=±b2 a2
(2分)b2 a
得点C坐标为(c,
),于是OC的斜率为kOC=b2 a
=
b2 a c
b2 ac
∵直线AB与直线OC平行,
∴kAB=kOC,即
=b a
,可得b=c(4分)b2 ac
∴椭圆的离心率e=
=c a
=c
b2+c2
=c
c2+c2