Home
Class 12
MATHS
The lengths of the tangents from any poi...

The lengths of the tangents from any point on the circle `15x^(2)+15y^(2)-48x+64y=0` to the two circles `5x^(2)+5y^(2)-24x+32y+75=0` and `5x^(2)+5y^(2)-48x+64y+300=0` are in the ratio

A

`1:2`

B

`2:3`

C

`3:4`

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the lengths of the tangents from a point on the first circle to the other two circles and then determine the ratio of these lengths. ### Step-by-Step Solution: 1. **Identify the First Circle:** The equation of the first circle is given as: \[ 15x^2 + 15y^2 - 48x + 64y = 0 \] We can rewrite this in standard form by dividing the entire equation by 15: \[ x^2 + y^2 - \frac{48}{15}x + \frac{64}{15}y = 0 \] Completing the square for \(x\) and \(y\): \[ \left(x - \frac{24}{15}\right)^2 + \left(y + \frac{32}{15}\right)^2 = \left(\frac{24^2 + 32^2}{15}\right) \] 2. **Identify the Second Circle:** The second circle is given by: \[ 5x^2 + 5y^2 - 24x + 32y + 75 = 0 \] Dividing by 5: \[ x^2 + y^2 - \frac{24}{5}x + \frac{32}{5}y + 15 = 0 \] Completing the square: \[ \left(x - \frac{12}{5}\right)^2 + \left(y + \frac{16}{5}\right)^2 = \left(\frac{12^2 + 16^2}{5} - 15\right) \] 3. **Identify the Third Circle:** The third circle is given by: \[ 5x^2 + 5y^2 - 48x + 64y + 300 = 0 \] Dividing by 5: \[ x^2 + y^2 - \frac{48}{5}x + \frac{64}{5}y + 60 = 0 \] Completing the square: \[ \left(x - \frac{24}{5}\right)^2 + \left(y + \frac{32}{5}\right)^2 = \left(\frac{24^2 + 32^2}{5} - 60\right) \] 4. **Length of Tangents:** The length of the tangent from a point \(P(a, b)\) on the first circle to the second circle is given by: \[ L_1 = \sqrt{S_1} = \sqrt{a^2 + b^2 - \frac{24}{5}a + \frac{32}{5}b + 15} \] The length of the tangent to the third circle is: \[ L_2 = \sqrt{S_2} = \sqrt{a^2 + b^2 - \frac{48}{5}a + \frac{64}{5}b + 60} \] 5. **Substituting \(a^2 + b^2\):** From the first circle, we have: \[ a^2 + b^2 = \frac{48}{15}a - \frac{64}{15}b \] Substitute this into \(L_1\) and \(L_2\). 6. **Finding the Ratio \(L_1 : L_2\):** After substituting and simplifying, we find that: \[ L_2 = 2L_1 \] Thus, the ratio of the lengths of the tangents is: \[ L_1 : L_2 = 1 : 2 \] ### Final Answer: The lengths of the tangents from any point on the first circle to the two circles are in the ratio \(1:2\).
Promotional Banner

Topper's Solved these Questions

  • THE CIRCLE

    ML KHANNA|Exercise Problem Set (6) (TRUE AND FALSE) |1 Videos
  • THE CIRCLE

    ML KHANNA|Exercise Problem Set (7) (MULTIPLE CHOICE QUESTIONS) |23 Videos
  • THE CIRCLE

    ML KHANNA|Exercise Problem Set (5) (FILL IN THE BLANKS) |2 Videos
  • TANGENTS AND NORMALS

    ML KHANNA|Exercise SELF ASSESSMENT TEST (MULTIPLE CHOICE QUESTIONS)|19 Videos
  • THE ELLIPSE

    ML KHANNA|Exercise SELF ASSESSMENT TEST|9 Videos

Similar Questions

Explore conceptually related problems

The lengths of the tangents from any point on the circle 15x^(2)+15y^(2)-48x+64y=0 to the two circles 5x^(2)+5y^(2)-24x+32y+75=0 5x^(2)+5y^(2)-48x+64y=0 are in the ratio

The length of the tangent from any point on the circle x^(2)+y^(2)-2x-4y-5=0 to the circle 2x^(2)+2y^(2)-4x-8y-7=0 is

The length of the tangent from a point on the circle x^(2)+y^(2)+4x6y-12=0 to the circle x^(2)+y^(2)+4x6y+4=0 is

The lengths of the tangents from any point on the circle x^(2)+y^(2)+8x+1=0 to the circles x^(2)+y^(2)+7x+1=0 and x^(2)+y^(2)+4x+1=0 are in the ratio

The length of the tangent from (0, 0) to the circle 2(x^(2)+y^(2))+x-y+5=0 , is

The length of the tangent from (1,1) to the circle 2x^(2)+2y^(2)+5x+3y+1=0 is

The length (in units) of tangent from point (5,1) to the circle x^(2)+y^(2)+6x-4y-3=0 is

ML KHANNA-THE CIRCLE -Problem Set (6) (MULTIPLE CHOICE QUESTIONS)
  1. The co-ordinates of the point from which the lengths of tangents to th...

    Text Solution

    |

  2. The co-ordinates of the point from which the length of tangents to the...

    Text Solution

    |

  3. The radical centre of three circles described on the three sides of a ...

    Text Solution

    |

  4. The radical centre of the circle x^(2)+y^(2)=1, x^(2)+y^(2)-2x=1 and x...

    Text Solution

    |

  5. Length of tangent from the radical centre of the three circles x^(2)+y...

    Text Solution

    |

  6. Locus of the point from which the difference of the squares of lengths...

    Text Solution

    |

  7. The length of tangent from (5,1) to the circle x^(2)+y^(2)+6x-4y-3=0 ...

    Text Solution

    |

  8. x^(2)+y^(2)+2lambdax +5=0 and x^(2)+y^(2)+2lambday+5=0 are the equatio...

    Text Solution

    |

  9. If the tangent at the point p on the circle x^(2)+y^(2)+6x+6y=2 meets ...

    Text Solution

    |

  10. The lengths of the tangents from any point on the circle 15x^(2)+15y^...

    Text Solution

    |

  11. The length of the tangent drawn from any point on the circle S=x^(2)+...

    Text Solution

    |

  12. A and B are two points (0,0) and (3a,0) respectively. Points P and Q a...

    Text Solution

    |

  13. If the distances from the origin of the centres of the three circles x...

    Text Solution

    |

  14. A pair of tangents are drawn from a point P to the circle x^(2)+y^(2)=...

    Text Solution

    |

  15. A point P moves so that length of tangent from P to the circle x^(2)+y...

    Text Solution

    |

  16. x^(2)+y^(2)-4x-2y-11=0 is a circle to which tangents are drawn from t...

    Text Solution

    |

  17. Equation of the circle coaxial with the circles 2x^(2)+2y^(2)-2x+6y-3=...

    Text Solution

    |

  18. ABCD is a square of side length 2. C(1) is a circle inscribed in the s...

    Text Solution

    |

  19. ABCD is a square of side length 2. C(1) is a circle inscribed in the s...

    Text Solution

    |

  20. ABCD is a square of side length 2. C(1) is a circle inscribed in the s...

    Text Solution

    |