The angle between the line joining the foci of an ellipse to one particular extremity of the minor axis is 90$$^\circ$$. The eccentricity of the ellipse is

S and T are the foci of an ellipse and B is an end point of the minor axis. If STB is an equilateral triangle, the eccentricity of the ellipse is

The length of the latus rectum of the ellipse is 16x² + 25y² = 400 is

The equation 8x² + 12y² $$-$$ 4x + 4y $$-$$ 1 = 0 represents