The eccentricity of an ellipse , with its centre at origin is $\large\frac{1}{2}$, If one of the directrices is $x=4$ then the equation of the ellipse is - Clay6.com, a Free resource for your JEE, AIPMT and Board Exam preparation

The eccentricity of an ellipse , with its centre at origin is $\large\frac{1}{2}$, If one of the directrices is $x=4$ then the equation of the ellipse is