Home
Class 12
MATHS
If the distance between the foci and the...

If the distance between the foci and the distance between the two directricies of the hyperbola `(x^2)/(a^2)-(y^2)/(b^2)=1` are in the ratio 3:2, then `b : a` is (a)`1:sqrt(2)` (b) `sqrt(3):sqrt(2)` (c)`1:2` (d) `2:1`

A

`1:sqrt2`

B

`sqrt3:sqrt2`

C

`1:2`

D

`2:1`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the ratio \( b : a \) given that the distance between the foci and the distance between the two directrices of the hyperbola \( \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 \) are in the ratio \( 3:2 \). ### Step-by-Step Solution: 1. **Identify the distances**: - The distance between the foci of the hyperbola is given by \( 2ae \), where \( e \) is the eccentricity. - The distance between the directrices is given by \( \frac{2a}{e} \). 2. **Set up the ratio**: - According to the problem, the ratio of the distance between the foci to the distance between the directrices is \( 3:2 \). - Therefore, we can write: \[ \frac{2ae}{\frac{2a}{e}} = \frac{3}{2} \] 3. **Simplify the ratio**: - Simplifying the left-hand side: \[ \frac{2ae \cdot e}{2a} = e^2 \] - Thus, we have: \[ e^2 = \frac{3}{2} \] 4. **Relate eccentricity to \( a \) and \( b \)**: - The eccentricity \( e \) for a hyperbola is defined as: \[ e^2 = 1 + \frac{b^2}{a^2} \] - Substituting \( e^2 = \frac{3}{2} \) into this equation gives: \[ \frac{3}{2} = 1 + \frac{b^2}{a^2} \] 5. **Solve for \( \frac{b^2}{a^2} \)**: - Rearranging the equation: \[ \frac{b^2}{a^2} = \frac{3}{2} - 1 = \frac{1}{2} \] 6. **Find the ratio \( b : a \)**: - Taking the square root of both sides: \[ \frac{b}{a} = \frac{1}{\sqrt{2}} \] - Therefore, the ratio \( b : a \) is: \[ b : a = 1 : \sqrt{2} \] ### Final Answer: The ratio \( b : a \) is \( 1 : \sqrt{2} \), which corresponds to option (a).

To solve the problem, we need to find the ratio \( b : a \) given that the distance between the foci and the distance between the two directrices of the hyperbola \( \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 \) are in the ratio \( 3:2 \). ### Step-by-Step Solution: 1. **Identify the distances**: - The distance between the foci of the hyperbola is given by \( 2ae \), where \( e \) is the eccentricity. - The distance between the directrices is given by \( \frac{2a}{e} \). ...
Promotional Banner

Topper's Solved these Questions

  • HYPERBOLA

    CENGAGE ENGLISH|Exercise MULTIPLE CORRECT ANSWERS TYPE|18 Videos
  • HYPERBOLA

    CENGAGE ENGLISH|Exercise COMOREHENSION TYPE|21 Videos
  • HYPERBOLA

    CENGAGE ENGLISH|Exercise CONCEPT APPLICATION EXERCISE 7.6|4 Videos
  • HIGHT AND DISTANCE

    CENGAGE ENGLISH|Exercise Archives|3 Videos
  • INDEFINITE INTEGRATION

    CENGAGE ENGLISH|Exercise Multiple Correct Answer Type|2 Videos

Similar Questions

Explore conceptually related problems

In an ellipse the distance between the foci is 8 and the distance between the directrices is 25. The length of major axis is : (A) 5sqrt(2) (B) 10sqrt(2) (C) 20sqrt(2) (D) none of these

The distance between the directrices of the hyperbola x=8s e ctheta,\ y=8\ t a ntheta, a. 8sqrt(2) b. 16sqrt(2) c. 4sqrt(2) d. 6sqrt(2)

If distance between the foci of an ellipse is 6 and distance between its directrices is 12, then length of its latus rectum is : (A)4 (B) 3sqrt2 (C)9 (D) 2sqrt2

The eccentricity of the hyperbola |sqrt((x-3)^2+(y-2)^2)-sqrt((x+1)^2+(y+1)^2)|=1 is ______

The eccentricity of the hyperbola |sqrt((x-3)^2+(y-2)^2)-sqrt((x+1)^2+(y+1)^2)|=1 is ______

The distance between the origin and the tangent to the curve y=e^(2x)+x^2 drawn at the point x=0 is (a) (1/sqrt(5)) (b) (2/sqrt(5)) (c) (-(1)/sqrt(5)) (d) (2/sqrt(3))

The length of the chord of the parabola y^2=x which is bisected at the point (2, 1) is (a) 2sqrt(3) (b) 4sqrt(3) (c) 3sqrt(2) (d) 2sqrt(5)

A parabola is drawn with focus at one of the foci of the ellipse (x^2)/(a^2)+(y^2)/(b^2)=1 . If the latus rectum of the ellipse and that of the parabola are same, then the eccentricity of the ellipse is (a) 1-1/(sqrt(2)) (b) 2sqrt(2)-2 (c) sqrt(2)-1 (d) none of these

The eccentricity of the hyperbola x=a/2(t+1/t), y=a/2(t-1/t) is a. sqrt(2) . b. sqrt(3) c. 2sqrt(3) d. 3sqrt(2)

The eccentricity of the hyperbola x^2-4y^2=1 is a. (sqrt(3))/2 b. (sqrt(5))/2 c. 2/(sqrt(3)) d. 2/(sqrt(5))

CENGAGE ENGLISH-HYPERBOLA-EXERCISES
  1. If the distance between the foci and the distance between the two di...

    Text Solution

    |

  2. The is a point P on the hyperbola (x^(2))/(16)-(y^(2))/(6)=1 such that...

    Text Solution

    |

  3. The equation, 2x^2+ 3y^2-8x-18y+35= K represents (a) no locus if k g...

    Text Solution

    |

  4. Let 'a' and 'b' be non-zero real numbers. Then, the equation (ax^2+ by...

    Text Solution

    |

  5. For the hyperbola x^2/ cos^2 alpha - y^2 /sin^2 alpha = 1;(0 lt alphal...

    Text Solution

    |

  6. Which of the following pairs may represent the eccentricities of two c...

    Text Solution

    |

  7. If a variable line has its intercepts on the coordinate axes ea n de^(...

    Text Solution

    |

  8. A hyperbola, having the transverse axis of length 2sin theta, is conf...

    Text Solution

    |

  9. If the distances of one focus of hyperbola from its directrices are 5 ...

    Text Solution

    |

  10. Let x^2/a^2+y^2/b^2=1 and x^2/A^2-y^2/B^2=1 be confocal (a > A and a> ...

    Text Solution

    |

  11. Two tangents are drawn from a point on hyperbola x^(2)-y^(2)=5 to the...

    Text Solution

    |

  12. Equation of the rectangular hyperbola whose focus is (1,-1) and the co...

    Text Solution

    |

  13. If two circles (x+4)^(2)+y^(2)=1 and (x-4)^(2)+y^(2)=9 are touched ext...

    Text Solution

    |

  14. If the vertex of a hyperbola bisects the distance between its center ...

    Text Solution

    |

  15. The eccentricity of the hyperbola whose length of the latus rectum is ...

    Text Solution

    |

  16. Let L L ' be the latus rectum through the focus of the hyperbola (x^2)...

    Text Solution

    |

  17. The eccentricity of the conjugate hyperbola of the hyperbola x^2-3y^2=...

    Text Solution

    |

  18. The locus of the point of intersection of the lines sqrt3 x- y-4sqrt3 ...

    Text Solution

    |

  19. lf the eccentricity of the hyperbola x^2 - y^2 sec^2 alpha=5 is sqrt3...

    Text Solution

    |

  20. The equation of the transvers and conjugate axes of a hyperbola are, ...

    Text Solution

    |