JEE Main
- Exam
- JEE Main
- Subject
- Mathematics
- Chapter
- Hyperbola
JEE Main · Mathematics · Hyperbola
If a directrix of a hyperbola centered at the origin and passing...
If a directrix of a hyperbola centered at the origin and passing through the point is ~and~its eccentricity is , then:
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
Let equation of hyperbola is
It passes through \left(4, - 2\sqrt{3}\right) ⇒ \dfrac{16}{a2} - \dfrac{12}{b2} = 1⇒ 16 - 12 \times \dfrac{a2}{b2} = a^{2} . . . \left(1\right)x = ⇒ a^{2} = e^{2} . . . \left(2\right)b^{2} = a^{2} \left(e^{2} - 1\right)⇒ e^{2} - 1 . . . \left(3\right)
From~ \left(1\right), \left(2\right) \text{ and } \left(3\right)16 - e^{2}⇒ 16e^{2} - 16 - 12 =