[" 5.A focus of an ellipse is at the origin.The directrix "],[" is the line "x=4" and the eccentricity is "(1)/(2)." Then "],[" the length of the semi-major axis is "]

A focus of an ellipse is at the origin the directrix is the line x=4 and the eccentricity is 1/2 . Then the length of semi major axis is

A focus of an ellipse is at the origin. The directrix is the line x""=""4 and the eccentricity is 1/2. Then the length of the semimajor axis is (1) 8/3 (2) 2/3 (3) 4/3 (4) 5/3

A focus of an ellipse is at the origin. The directrix is the line x""=""4 and the eccentricity is 1/2. Then the length of the semimajor axis is (1) 8/3 (2) 2/3 (3) 4/3 (4) 5/3

A focus of an ellipse is at the origin. The directrix is the line x=4 and the eccenricityh is 1/2 , then length of semi-major axis is

The length of the semi-major axis of an ellipse is 13 and its eccentricity is 12/13. Then the length of the semi-minor axis is

IF the distance between a focus and corresponding directrix of an ellipse be 8 and the eccentricity be 1/2 , then length of the minor axis is

IF the distance between a focus and corresponding directrix of an ellipse be 8 and the eccentricity be 1/2 , then length of the minor axis is

The equation of the ellipse whose focus is (1,-1) the directrix the line x-y-3=0 and eccentricity (1)/(2) is