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If the circles x^(2)+y^(2) +5Kx+2y +...

If the circles `x^(2)+y^(2) +5Kx+2y + K=0 and2(x^(2)+y^(2))+2Kx +3y-1=0, (KinR)`, intersect at the points P and Q, then the line 4x + 5y - K = 0 passes through P and Q, for

A

no value of K

B

exactly one value of K

C

exactly two value of K

D

infinitely many value of K

Text Solution

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The correct Answer is:
To solve the problem step by step, we need to analyze the given circles and the line. ### Step 1: Write down the equations of the circles The equations of the circles are given as: 1. \( x^2 + y^2 + 5Kx + 2y + K = 0 \) (Circle 1) 2. \( 2(x^2 + y^2) + 2Kx + 3y - 1 = 0 \) (Circle 2) ### Step 2: Simplify the second circle's equation We can simplify the second circle's equation by dividing everything by 2: \[ x^2 + y^2 + Kx + \frac{3}{2}y - \frac{1}{2} = 0 \] This is now the equation of Circle 2. ### Step 3: Set up the equations for the common chord The common chord of two circles can be found using the formula \( S_1 - S_2 = 0 \), where \( S_1 \) and \( S_2 \) are the equations of the circles. Let: - \( S_1 = x^2 + y^2 + 5Kx + 2y + K \) - \( S_2 = x^2 + y^2 + Kx + \frac{3}{2}y - \frac{1}{2} \) Now, we find \( S_1 - S_2 \): \[ S_1 - S_2 = (x^2 + y^2 + 5Kx + 2y + K) - (x^2 + y^2 + Kx + \frac{3}{2}y - \frac{1}{2}) = 0 \] This simplifies to: \[ (5K - K)x + \left(2 - \frac{3}{2}\right)y + \left(K + \frac{1}{2}\right) = 0 \] \[ (4K)x + \frac{1}{2}y + \left(K + \frac{1}{2}\right) = 0 \] ### Step 4: Rearranging the equation We can rearrange this equation to get: \[ 4Kx + \frac{1}{2}y + K + \frac{1}{2} = 0 \] ### Step 5: Compare with the line equation The line equation given is: \[ 4x + 5y - K = 0 \] We need to ensure that the coefficients of \( x \) and \( y \) in the common chord equation match those in the line equation. ### Step 6: Set up the equations based on coefficients From the equations: 1. Coefficient of \( x \): \( 4K = 4 \) → \( K = 1 \) 2. Coefficient of \( y \): \( \frac{1}{2} = 5 \) → This is not possible. ### Step 7: Solve for K from the first coefficient From the first coefficient: \[ 4K = 4 \implies K = 1 \] ### Step 8: Check for contradictions Now substituting \( K = 1 \) into the second coefficient gives: \[ \frac{1}{2} = 5 \implies \text{Contradiction} \] ### Conclusion Since we have reached a contradiction, it means there is no value of \( K \) such that the line \( 4x + 5y - K = 0 \) passes through both points \( P \) and \( Q \). ### Final Answer There is no value of \( K \) for which the line passes through points \( P \) and \( Q \). ---

To solve the problem step by step, we need to analyze the given circles and the line. ### Step 1: Write down the equations of the circles The equations of the circles are given as: 1. \( x^2 + y^2 + 5Kx + 2y + K = 0 \) (Circle 1) 2. \( 2(x^2 + y^2) + 2Kx + 3y - 1 = 0 \) (Circle 2) ### Step 2: Simplify the second circle's equation ...
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