EllipseEasy
Question
The eccentricity of an ellipse, with its centre at the origin, is 
. If one of the directrices is x = 4, then the equation of the ellipse is
. If one of the directrices is x = 4, then the equation of the ellipse isOptions
A.3x2 + 4y2 = 1
B.3x2 + 4y2 = 12
C.4x2 + 3y2 = 12
D.4x2 + 3y2 = 1
Solution
Equation of directrix is x = a/e = 4 ⇒ a = 2
b2 = a2 (1 - e2) ⇒ b2 = 3
Hence equation of ellipse is 3x2 + 4y2 = 12.
b2 = a2 (1 - e2) ⇒ b2 = 3
Hence equation of ellipse is 3x2 + 4y2 = 12.
Create a free account to view solution
View Solution FreeMore Ellipse Questions
Which one of the following is the common tangent to the ellipses, $\frac{x^{2}}{a^{2} + b^{2}} + \frac{y^{2}}{b^{2}} = 1...If $P(\theta)$ and $Q\left( \frac{\pi}{2} + \theta \right)$ are two points on the ellipse $\frac{x^{2}}{a^{2}} + \frac{y...If straight line $\frac{ax}{3} + \frac{by}{4} = c$ is a normal to the ellipse $\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}}...If $\frac{x^2}{36-\lambda} + \frac{y^2}{25-\lambda} = 1$ is the equation of a conic, where $\lambda < 25$, then which of...An ellipse has OB as semi minor axis, F and F′ its focii and the angle FBF′ is a right angle. Then the eccen...