$\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1$ উপবৃত্ত; $a=b$ হলে নিয়ামকের সমীকরণ-

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

The equation of the ellipse with axes along the x-axis and the y-axis, which passes through the points P(4, 3) and Q (6, 2) is

vertices of an ellipse are $(0,\pm 10)$ and its eccentricity $e=4/5$ then its equation is ;