Medium MCQ +4 / -1 PYQ · JEE Mains 2022

If the line $x-1=0$ is a directrix of the hyperbola $k x^{2}-y^{2}=6$, then the hyperbola passes through the point :

  1. A $(-2 \sqrt{5}, 6)$
  2. B $(-\sqrt{5}, 3)$
  3. C $(\sqrt{5},-2)$ Correct answer
  4. D $(2 \sqrt{5}, 3 \sqrt{6})$

Solution

<p>Given hyperbola : ${{{x^2}} \over {6/k}} - {{{y^2}} \over 6} = 1$</p> <p>Eccentricity $= e = \sqrt {1 + {6 \over {6/k}}} = \sqrt {1 + k}$</p> <p>Directrices : $$x = \, \pm \,{a \over e} \Rightarrow x = \, \pm \,{{\sqrt 6 } \over {\sqrt k \sqrt {k + 1} }}$$</p> <p>As given : ${{\sqrt 6 } \over {\sqrt k \sqrt {k + 1} }} = 1$</p> <p>$\Rightarrow k = 2$</p> <p>Here hyperbola is ${{{x^2}} \over 3} - {{{y^2}} \over 6} = 1$</p> <p>Checking the option gives $\left( {\sqrt 5 , - 2} \right)$ satisfies it.</p>

About this question

Subject: Mathematics · Chapter: Conic Sections · Topic: Parabola

This question is part of PrepWiser's free JEE Main question bank. 146 more solved questions on Conic Sections are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →