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If alpha,beta be the roots of x^(2)-px+q...

If `alpha,beta` be the roots of `x^(2)-px+q=0`, find the value of `alpha^(5)beta^(7)+alpha^(7)beta^(5)` in terms of p and q.

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To find the value of \( \alpha^5 \beta^7 + \alpha^7 \beta^5 \) in terms of \( p \) and \( q \), where \( \alpha \) and \( \beta \) are the roots of the quadratic equation \( x^2 - px + q = 0 \), we can follow these steps: ### Step 1: Identify the roots and their relationships From Vieta's formulas, we know: - The sum of the roots \( \alpha + \beta = p \) - The product of the roots \( \alpha \beta = q \) ### Step 2: Rewrite the expression We need to express \( \alpha^5 \beta^7 + \alpha^7 \beta^5 \) in a more manageable form. We can factor it: \[ \alpha^5 \beta^7 + \alpha^7 \beta^5 = \alpha^5 \beta^5 (\beta^2 + \alpha^2) \] ### Step 3: Simplify \( \beta^2 + \alpha^2 \) Using the identity \( \alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta \), we can substitute: \[ \alpha^2 + \beta^2 = p^2 - 2q \] ### Step 4: Calculate \( \alpha^5 \beta^5 \) We can express \( \alpha^5 \beta^5 \) as: \[ \alpha^5 \beta^5 = (\alpha \beta)^5 = q^5 \] ### Step 5: Combine the results Now substituting back into our expression: \[ \alpha^5 \beta^7 + \alpha^7 \beta^5 = q^5 (p^2 - 2q) \] ### Final Result Thus, the value of \( \alpha^5 \beta^7 + \alpha^7 \beta^5 \) in terms of \( p \) and \( q \) is: \[ \alpha^5 \beta^7 + \alpha^7 \beta^5 = q^5 (p^2 - 2q) \]
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ICSE-QUADRATIC EQUATIONS-CHAPTER TEST
  1. For what values of m will the equation x^(2)-2mx+7m-12=0 have (i) equa...

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  2. If one root of 2x^(2)-5x+k=0 be double the other, find the value of k.

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  3. If alpha,beta be the roots of the equation x^(2)-x-1=0, determine the ...

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  4. If the roots of the equation ax^(2)+bx+c=0 be in the ratio 3:4, show t...

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  5. If x is real, prove that the quadratic expression (i) (x-2)(x+3)+7 is ...

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  6. Draw the graph of the quadratic function x^(2)-4x+3 and hence find the...

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  7. For what real values of a, will the expression x^(2)-ax+1-2a^(2), for ...

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  8. If x be real, prove that the value of (2x^(2)-2x+4)/(x^(2)-4x+3) canno...

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  9. If the roots of the equation qx^(2)+2px+2q=0 are real and unequal, pro...

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  10. If alpha,beta be the roots of x^(2)-px+q=0, find the value of alpha^(5...

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  11. If the difference between the roots of the equation x^(2)+ax+1=0 is le...

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  12. Let alpha,beta be the roots of the equation x^(2)-px+r=0 and alpha//2,...

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  13. alpha,beta are the roots of ax^(2)+2bx+c=0 and alpha+delta,beta+delta ...

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  14. If alpha,beta are the roots of the equation x^(2)-2x-1=0, then what is...

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  15. If the roots of the quadratic equation x^(2)+px+q=0 are tan 30^(@) and...

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  16. If both the roots of the quadratic equation x^(2)-2kx+k^(2)+k-5=0 are ...

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  17. If alpha and beta are the roots of ax^(2)+bx+c=0 and if px^(2)+qx+r=0...

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  18. The quadratic equations x^(2)-6x+a=0 and x^(2)-cx+6=0 have one root in...

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

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  20. If alpha,beta be the roots of x^(2)-a(x-1)+b=0, then the value of (1)/...

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