An ellipse has OB as semi-minor axis, F and F' its foci and the angle FBF' is a right angle. Then, the eccentricity of the ellipse is
AIEEE Solved Paper-2005
A)\[1/\sqrt{3}\]
B) \[1/4\]
C) \[1/2\]
D) \[1/\sqrt{2}\]
Correct Answer:
D
Solution :
(is an isosceles triangle) and Alternate Solution Here, F and F' are foci of an ellipse, whose coordinates areandrespectively and coordinates of B are (0, b). Slope of and slope of