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If the equadratic equation 4x ^(2) -2x -...

If the equadratic equation `4x ^(2) -2x -m =0 and 4p (q-r) x ^(2) -2p (r-p) x+r (p-q)-=0` have a common root such that second equation has equal roots then the vlaue of m will be :

A

0

B

1

C

2

D

3

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The correct Answer is:
To solve the problem step by step, we will analyze the given quadratic equations and find the value of \( m \). ### Step 1: Identify the equations The first quadratic equation is: \[ 4x^2 - 2x - m = 0 \] The second quadratic equation is: \[ 4p(q - r)x^2 - 2p(r - p)x + r(p - q) = 0 \] ### Step 2: Understand the conditions We know that these two equations have a common root, and the second equation has equal roots. For a quadratic equation \( ax^2 + bx + c = 0 \) to have equal roots, the discriminant must be zero: \[ D = b^2 - 4ac = 0 \] ### Step 3: Find the discriminant of the second equation For the second equation, the coefficients are: - \( a = 4p(q - r) \) - \( b = -2p(r - p) \) - \( c = r(p - q) \) The discriminant \( D \) is: \[ D = (-2p(r - p))^2 - 4(4p(q - r))(r(p - q)) \] Calculating \( D \): \[ D = 4p^2(r - p)^2 - 16p(q - r)(r(p - q)) \] Setting \( D = 0 \) for equal roots: \[ 4p^2(r - p)^2 - 16p(q - r)(r(p - q)) = 0 \] ### Step 4: Solve for the common root Let’s assume the common root is \( \alpha \). Then, substituting \( x = \alpha \) into the first equation: \[ 4\alpha^2 - 2\alpha - m = 0 \quad \Rightarrow \quad m = 4\alpha^2 - 2\alpha \] ### Step 5: Substitute \( \alpha \) into the second equation Since the second equation has equal roots, we can assume \( \alpha \) is one of the roots. We can also assume a specific value for \( \alpha \) to simplify our calculations. Let's assume \( \alpha = -\frac{1}{2} \). Substituting \( \alpha = -\frac{1}{2} \) into the first equation: \[ m = 4\left(-\frac{1}{2}\right)^2 - 2\left(-\frac{1}{2}\right) \] Calculating this: \[ m = 4 \cdot \frac{1}{4} + 1 = 1 + 1 = 2 \] ### Conclusion The value of \( m \) is: \[ \boxed{2} \]
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VK JAISWAL ENGLISH-QUADRATIC EQUATIONS -EXERCISE (SUBJECTIVE TYPE PROBLEMS)
  1. If the equadratic equation 4x ^(2) -2x -m =0 and 4p (q-r) x ^(2) -2p (...

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  2. Let f(x) = ax^2 + bx + c where a,b,c are integers. If sin\ pi/7 * sin\...

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  3. Let a,b,c,d be distinct integers such that the equation (x-a) (x-b) (x...

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  4. Consider the equation (x^2 + x + 1)^2-(m-3)(x^2 + x + 1) +m=0--(1), w...

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  5. The number of positive integral values of m, m le 16 for which the equ...

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  6. If the equation (m^(2) -12 )x^(4) -8x ^(2)-4=0 has no real roots, then...

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  7. The least rositive integral value of 'x' satisfying (e ^(x) -2) (sin (...

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  8. The integral values of x for which x^2 +17x+71 is perfect square of a ...

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  10. The number of real values of 'a' for which the largest value of the fu...

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  11. The number of all values of n, (whre pi is a whole number ) for which ...

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  12. The number of negative intergral values of m for which the expression ...

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  13. If the expression ax ^(4)+bx^(3)-x ^(2)+2x+3 has the remainder 4x +3 w...

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  14. The smallest value of k for which both roots of the equation x^(2)-8kx...

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  15. If x ^(2) -3x+2 is a factor of x ^(4) -px ^(2) +q=0, then p+q=

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  16. The sum of all real values of k for which the expression x ^(2)+2xy +k...

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  17. The curve y=(lambda=1)x^2+2 intersects the curve y=lambdax+3 in exactl...

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  18. Find the number of integral vaues of 'a' for which the range of functi...

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  19. When x ^(100) is divided by x ^(2) -3x +2, the remainder is (2 ^(k +1)...

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  20. Let p(x)=0 be a polynomial equation of the least possible degree, with...

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  21. The range of value's of k for which the equation 2 cos^(4) x - sin^(4...

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