EllipseHard
Question
Let the foci of hyperbola coincide with the foci of the ellipse $\frac{x^{2}}{36} + \frac{y^{2}}{16} = 1$. If the eccentricity of the hyperbola is 5 , then the length of its latus rectum is:
Options
A.12
B.16
C.$\frac{96}{\sqrt{5}}$
D.$24\sqrt{5}$
Solution
Let $e_{1}$ be eccentricity of ellipse
$$\Rightarrow e_{1} = \sqrt{1 - \frac{16}{36}} = \sqrt{1 - \frac{4}{9}} = \frac{\sqrt{5}}{3} $$So ${ae}_{1} = 6 \cdot \frac{\sqrt{5}}{3} = 2\sqrt{5}$
Now H : $\frac{x^{2}}{p^{2}} - \frac{y^{2}}{q^{2}} = 1$
p.e $= {ae}_{1}$
p. $5 = 2\sqrt{5}$
$$p = \frac{2}{\sqrt{5}} \Rightarrow e^{2} = 1 + \frac{q^{2}}{p^{2}} \Rightarrow 25 = 1 + \frac{5q^{2}}{4} \Rightarrow q^{2} = \frac{96}{5} $$So length of $LR\frac{2q^{2}}{p} = \frac{96}{\sqrt{5}}$
Create a free account to view solution
View Solution FreeMore Ellipse Questions
If a > 2b > 0 then positive value of m for which y = mx - b is a common tangent tox2 + y2 = b2 and (x - a)2 + y2 = b2 is...If the eccentricity of the hyperbola x2 - y2 sec2θ = 4 is √3 times the eccentricity of the ellipse x2sec2_...Eccentric angle of a point on the ellipse x2 + 3y2 = 6 at a distance 2 units from the centre of the ellipse is -...In an ellipse the distance between its foci is 6 and its minor axis is 8. Then its eccentricity is-...Locus of the point which divides double ordinate of the ellipse = 1 in the ratio 1 : 2 internally, is...