- Home
- Standard 11
- Mathematics
10-2. Parabola, Ellipse, Hyperbola
easy
The equation of the director circle of the hyperbola $\frac{{{x^2}}}{{16}} - \frac{{{y^2}}}{4} = 1$ is given by
A
${x^2} + {y^2} = 16$
B
${x^2} + {y^2} = 4$
C
${x^2} + {y^2} = 20$
D
${x^2} + {y^2} = 12$
Solution
(d) Equation of ‘director-circle’ of hyperbola is ${x^2} + {y^2} = {a^2} – {b^2}$.
Here ${a^2} = 16,\,{b^2} = 4$
$\therefore $ ${x^2} + {y^2} = 12$ is the required ‘director circle’.
Standard 11
Mathematics
Similar Questions
Let $H : \frac{ x ^2}{ a ^2}-\frac{ y ^2}{ b ^2}=1$, where $a > b >0$, be $a$ hyperbola in the $xy$-plane whose conjugate axis $LM$ subtends an angle of $60^{\circ}$ at one of its vertices $N$. Let the area of the triangle $LMN$ be $4 \sqrt{3}$..
List $I$ | List $II$ |
$P$ The length of the conjugate axis of $H$ is | $1$ $8$ |
$Q$ The eccentricity of $H$ is | $2$ ${\frac{4}{\sqrt{3}}}$ |
$R$ The distance between the foci of $H$ is | $3$ ${\frac{2}{\sqrt{3}}}$ |
$S$ The length of the latus rectum of $H$ is | $4$ $4$ |
The correct option is: