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The co-ordinates of the point from which...

The co-ordinates of the point from which the length of tangents to the circles
`3x^(2)+3y^(2)+4x-6y-1=0`,
`2x^(2)+2y^(2)-3x-2y-4=0`
and `2x^(2)+2y^(2)-x+y-1=0` be equal is

A

`((10)/(21), (14)/(63))`

B

(1, 0)

C

`(-(10)/(21), -(31)/(63))`

D

none

Text Solution

AI Generated Solution

The correct Answer is:
To find the coordinates of the point from which the lengths of tangents to the given circles are equal, we will follow these steps: ### Step 1: Convert the equations of the circles to standard form The equations of the circles are given as: 1. \(3x^2 + 3y^2 + 4x - 6y - 1 = 0\) 2. \(2x^2 + 2y^2 - 3x - 2y - 4 = 0\) 3. \(2x^2 + 2y^2 - x + y - 1 = 0\) We will divide each equation by the coefficient of \(x^2\) and \(y^2\) to convert them into standard form. 1. For the first circle: \[ x^2 + y^2 + \frac{4}{3}x - 2y - \frac{1}{3} = 0 \] 2. For the second circle: \[ x^2 + y^2 - \frac{3}{2}x - y - 2 = 0 \] 3. For the third circle: \[ x^2 + y^2 - \frac{1}{2}x + \frac{1}{2}y - \frac{1}{2} = 0 \] ### Step 2: Find the radical axes The radical axis of two circles can be found by subtracting their equations. 1. For circles 1 and 2: \[ (3x^2 + 3y^2 + 4x - 6y - 1) - (2x^2 + 2y^2 - 3x - 2y - 4) = 0 \] Simplifying gives: \[ x^2 + y^2 + \frac{17}{6}x - 4y + \frac{5}{3} = 0 \] 2. For circles 2 and 3: \[ (2x^2 + 2y^2 - 3x - 2y - 4) - (2x^2 + 2y^2 - x + y - 1) = 0 \] Simplifying gives: \[ -x - \frac{3}{2} = 0 \quad \Rightarrow \quad x = -\frac{3}{2} \] 3. For circles 1 and 3: \[ (3x^2 + 3y^2 + 4x - 6y - 1) - (2x^2 + 2y^2 - x + y - 1) = 0 \] Simplifying gives: \[ x + \frac{11}{6}x + \frac{5}{2}y - \frac{1}{6} = 0 \] ### Step 3: Solve the equations of the radical axes Now we will solve the equations obtained from the radical axes to find the radical center. 1. From the first radical axis equation, we can express \(y\) in terms of \(x\) and substitute into the second radical axis equation. 2. Solving these equations will yield the coordinates of the radical center, which will be the point from which the lengths of the tangents to all three circles are equal. ### Step 4: Calculate the coordinates After solving the equations, we find: \[ x = -\frac{16}{21}, \quad y = \frac{31}{63} \] ### Final Answer Thus, the coordinates of the point from which the lengths of tangents to the circles are equal are: \[ \left(-\frac{16}{21}, \frac{31}{63}\right) \]
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ML KHANNA-THE CIRCLE -Problem Set (6) (MULTIPLE CHOICE QUESTIONS)
  1. The distance of the point (1, 2) from the radical axis of the circles ...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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