An ellipse has OB as semi minor axis, F and its focii and the angle is a right angle. Then the eccentricity of the ellipse is
- (A)✓ Correct
- (B)
- (C)
- (D)
Answer: (A)
Solution
Let be the end of the semi-minor axis and let the foci be and . Each focal distance is . With the right angle at , the Pythagorean relation gives , so and , hence .
JEE Main · 2005 · 08 May 2005 · Offline · Single correct option