If the angle between the straight lines joining foci and the ends of minor axis of the ellipse `x^2/a^2+y^2/b^2=1` is `pi/2` then the eccentricity is

If the angle between the lines joining the end points of minor axis of an ellipse with its foci is pi/2, then the eccentricity of the ellipse is

If the angle between the lines joining the end points of minor axis of an elipes with its one focus is pi/2, then the eccentricity of the ellipse is-

If the angle between the lines joining the Foci to an extremity of minor axis of an ellipse is " 90^(@). " Its eccentricity is ' e ' then " 8e^(2) " is "]