Eccentricity of the ellipse $4{x^2} + {y^2} - 8x + 2y + 1 = 0$ is
$1/\sqrt 3 $
$\sqrt 3 /2$
$1/2$
None of these
The equations of the tangents of the ellipse $9{x^2} + 16{y^2} = 144$ which passes through the point $(2, 3)$ is
Length of common chord of the ellipse ${\frac{{\left( {x - 2} \right)}}{9}^2} + {\frac{{\left( {y + 2} \right)}}{4}^2} = 1$ and the circle ${x^2} + {y^2} - 4x + 2y + 4 = 0$
The eccentricity of an ellipse, with its centre at the origin, is $\frac{1}{2}$. If one of the directrices is $x = 4$, then the equation of the ellipse is
Find the equation of the ellipse, whose length of the major axis is $20$ and foci are $(0,\,\pm 5)$