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If alpha,beta are the roots of the equat...

If `alpha,beta` are the roots of the equation `3x^(2)-6x+4=0`, find the value of
`((alpha)/(beta)+(beta)/(alpha))+2((1)/(alpha)+(1)/(beta))+3alphabeta`.

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To solve the problem, we need to find the value of the expression: \[ \frac{\alpha}{\beta} + \frac{\beta}{\alpha} + 2\left(\frac{1}{\alpha} + \frac{1}{\beta}\right) + 3\alpha\beta \] where \(\alpha\) and \(\beta\) are the roots of the quadratic equation: \[ 3x^2 - 6x + 4 = 0 \] ### Step 1: Identify coefficients and calculate sum and product of roots The standard form of a quadratic equation is \(ax^2 + bx + c = 0\). Here, we have: - \(a = 3\) - \(b = -6\) - \(c = 4\) Using Vieta's formulas: - The sum of the roots \(\alpha + \beta = -\frac{b}{a} = -\frac{-6}{3} = 2\) - The product of the roots \(\alpha\beta = \frac{c}{a} = \frac{4}{3}\) ### Step 2: Calculate \(\frac{\alpha}{\beta} + \frac{\beta}{\alpha}\) Using the identity: \[ \frac{\alpha}{\beta} + \frac{\beta}{\alpha} = \frac{\alpha^2 + \beta^2}{\alpha\beta} \] We can express \(\alpha^2 + \beta^2\) using the formula: \[ \alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta \] Substituting the values we found: \[ \alpha^2 + \beta^2 = (2)^2 - 2\left(\frac{4}{3}\right) = 4 - \frac{8}{3} = \frac{12}{3} - \frac{8}{3} = \frac{4}{3} \] Now substituting back to find \(\frac{\alpha}{\beta} + \frac{\beta}{\alpha}\): \[ \frac{\alpha}{\beta} + \frac{\beta}{\alpha} = \frac{\frac{4}{3}}{\frac{4}{3}} = 1 \] ### Step 3: Calculate \(2\left(\frac{1}{\alpha} + \frac{1}{\beta}\right)\) Using the identity: \[ \frac{1}{\alpha} + \frac{1}{\beta} = \frac{\alpha + \beta}{\alpha\beta} \] Substituting the values: \[ \frac{1}{\alpha} + \frac{1}{\beta} = \frac{2}{\frac{4}{3}} = \frac{2 \cdot 3}{4} = \frac{6}{4} = \frac{3}{2} \] Now, multiplying by 2: \[ 2\left(\frac{1}{\alpha} + \frac{1}{\beta}\right) = 2 \cdot \frac{3}{2} = 3 \] ### Step 4: Calculate \(3\alpha\beta\) Substituting the product of the roots: \[ 3\alpha\beta = 3 \cdot \frac{4}{3} = 4 \] ### Step 5: Combine all parts Now we combine all the parts we calculated: \[ \frac{\alpha}{\beta} + \frac{\beta}{\alpha} + 2\left(\frac{1}{\alpha} + \frac{1}{\beta}\right) + 3\alpha\beta = 1 + 3 + 4 = 8 \] ### Final Answer Thus, the value of the expression is: \[ \boxed{8} \]
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ICSE-QUADRATIC EQUATIONS-EXERCISE 10 (c)
  1. If alpha,beta are the roots of the equation x^(2)+px+q=0, find the val...

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  2. If the roots of the equation x^(2)+px+7=0 are denoted by alpha and bet...

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  3. If alpha,beta are the roots of the equation 3x^(2)-6x+4=0, find the va...

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  4. If alpha,beta are the roots of ax^(2)+bx+c=0, find the value of (i) ...

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  5. If the sum of the roots of the equation x^(2)-px+q=0 be m times their ...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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