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The roots of the equation px^(2)-2(p+1)x...

The roots of the equation `px^(2)-2(p+1)x+3p=0` are `alpha and beta`. If `alpha-beta=2`, calculate the value of `alpha,beta` and p.

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To solve the equation \( px^2 - 2(p+1)x + 3p = 0 \) given that the roots \( \alpha \) and \( \beta \) satisfy \( \alpha - \beta = 2 \), we will follow these steps: ### Step 1: Identify the coefficients The coefficients of the quadratic equation are: - \( a = p \) - \( b = -2(p + 1) \) - \( c = 3p \) ### Step 2: Use the relationships of roots From Vieta's formulas, we know: 1. The sum of the roots \( \alpha + \beta = -\frac{b}{a} = \frac{2(p + 1)}{p} \) 2. The product of the roots \( \alpha \beta = \frac{c}{a} = \frac{3p}{p} = 3 \) ### Step 3: Express \( \alpha \) and \( \beta \) Given \( \alpha - \beta = 2 \), we can express \( \alpha \) and \( \beta \) in terms of their sum and difference: - Let \( \alpha + \beta = S \) and \( \alpha - \beta = D \). - Then, we have: \[ \alpha = \frac{S + D}{2} = \frac{\frac{2(p + 1)}{p} + 2}{2} = \frac{2(p + 1) + 2p}{2p} = \frac{4p + 2}{2p} = \frac{2p + 1}{p} \] \[ \beta = \frac{S - D}{2} = \frac{\frac{2(p + 1)}{p} - 2}{2} = \frac{2(p + 1) - 2p}{2p} = \frac{2}{2p} = \frac{1}{p} \] ### Step 4: Calculate the product of the roots Now, we can set up the equation using the product of the roots: \[ \alpha \beta = 3 \] Substituting the values of \( \alpha \) and \( \beta \): \[ \left(\frac{2p + 1}{p}\right) \left(\frac{1}{p}\right) = 3 \] This simplifies to: \[ \frac{2p + 1}{p^2} = 3 \] ### Step 5: Solve for \( p \) Cross-multiplying gives: \[ 2p + 1 = 3p^2 \] Rearranging this gives: \[ 3p^2 - 2p - 1 = 0 \] ### Step 6: Factor or use the quadratic formula We can factor this quadratic equation: \[ 3p^2 - 3p + p - 1 = 0 \] Factoring gives: \[ (3p + 1)(p - 1) = 0 \] Thus, \( p = -\frac{1}{3} \) or \( p = 1 \). ### Step 7: Find \( \alpha \) and \( \beta \) for each value of \( p \) 1. For \( p = 1 \): \[ \alpha = \frac{2(1) + 1}{1} = 3, \quad \beta = \frac{1}{1} = 1 \] So, \( \alpha = 3 \), \( \beta = 1 \). 2. For \( p = -\frac{1}{3} \): \[ \alpha = \frac{2(-\frac{1}{3}) + 1}{-\frac{1}{3}} = \frac{-\frac{2}{3} + 1}{-\frac{1}{3}} = \frac{\frac{1}{3}}{-\frac{1}{3}} = -1 \] \[ \beta = \frac{1}{-\frac{1}{3}} = -3 \] So, \( \alpha = -1 \), \( \beta = -3 \). ### Conclusion The valid solution that satisfies \( \alpha - \beta = 2 \) is: - \( p = 1 \) - \( \alpha = 3 \) - \( \beta = 1 \)
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ICSE-QUADRATIC EQUATIONS-EXERCISE 10 (c)
  1. If the sum of the roots of the equation x^(2)-px+q=0 be m times their ...

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  2. If one root of the equation x^(2)+ax+8=0 is 4 while the equation x^(2)...

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  3. Find the value of a for which one root of the quadratic equation (a^(2...

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  4. If alpha,beta are the roots of the equation ax^(2)-bx+b=0, prove that ...

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  5. If alpha and beta are the roots of the equation x^(2)+x-7=0, form the ...

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  6. If alpha and beta are the roots of the equation 2x^(2)+3x+2=0, find th...

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  7. Find the equation whose roots are (alpha)/(beta) and (beta)/(alpha), w...

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  8. If alpha and beta are the roots of the equation 2x^(2)-3x+1=0, form th...

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  9. If a ne b and a^(2)=5a-3,b^(2)=5b-3, then form that equation whose roo...

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  10. Given that alpha and beta are the roots of the equation x^(2)=x+7. (...

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  11. Given that alpha and beta are the roots of the equation x^(2)-x+7=0, f...

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  12. Given that alpha and beta are the roots of the equation 2x^(2)-3x+4=0,...

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  13. The roots of the quadratic equation x^(2)+px+8=0 are alpha and beta. ...

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  14. If the roots of x^(2)-bx+c=0 be two consecutive integers, then find th...

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  15. The roots of the equation px^(2)-2(p+1)x+3p=0 are alpha and beta. If a...

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  16. The roots of the equation ax^(2)+bx+c=0 are alpha and beta. Form the q...

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  17. Two candidates attempt to solve a quadratic equation of the form x^(2)...

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  18. Given that alpha and beta are the roots of the equation x^(2)=7x+4, ...

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  19. The ratio of the roots of the equation x^(2)+alphax+alpha+2=0 is 2. fi...

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  20. If (1-p) is a root of the quadratic equation x^(2)+px+(1-p)=0, then it...

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