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If roots of equation 2x^(4) - 3x^(3) + 2...

If roots of equation `2x^(4) - 3x^(3) + 2x^2 - 7x -1 = 0` are `alpha, beta, gamma` and 5 then value of `sum(alpha+1)/alpha` is equal to:

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To solve the equation \(2x^4 - 3x^3 + 2x^2 - 7x - 1 = 0\) and find the value of \(\sum \frac{\alpha + 1}{\alpha}\) where the roots are \(\alpha, \beta, \gamma\), and \(5\), we will follow these steps: ### Step 1: Understand the expression We need to evaluate: \[ \sum \frac{\alpha + 1}{\alpha} = \sum \left(1 + \frac{1}{\alpha}\right) = 4 + \sum \frac{1}{\alpha} \] Here, we have four roots: \(\alpha, \beta, \gamma, \delta\) (where \(\delta = 5\)). ### Step 2: Calculate the sum of the roots Using Vieta's formulas, for the polynomial \(2x^4 - 3x^3 + 2x^2 - 7x - 1 = 0\): - The sum of the roots \(\alpha + \beta + \gamma + \delta = -\frac{b}{a} = -\frac{-3}{2} = \frac{3}{2}\). ### Step 3: Substitute \(\delta = 5\) We know one of the roots is \(5\): \[ \alpha + \beta + \gamma + 5 = \frac{3}{2} \] Thus, \[ \alpha + \beta + \gamma = \frac{3}{2} - 5 = \frac{3}{2} - \frac{10}{2} = -\frac{7}{2} \] ### Step 4: Calculate the sum of the products of the roots taken three at a time Using Vieta's again, the sum of the products of the roots taken three at a time is given by: \[ \alpha \beta \gamma + \alpha \beta \delta + \alpha \gamma \delta + \beta \gamma \delta = \frac{d}{a} = -\frac{-7}{2} = \frac{7}{2} \] Substituting \(\delta = 5\): \[ \alpha \beta \gamma + 5(\alpha + \beta + \gamma) = \frac{7}{2} \] Substituting \(\alpha + \beta + \gamma = -\frac{7}{2}\): \[ \alpha \beta \gamma + 5\left(-\frac{7}{2}\right) = \frac{7}{2} \] \[ \alpha \beta \gamma - \frac{35}{2} = \frac{7}{2} \] \[ \alpha \beta \gamma = \frac{7}{2} + \frac{35}{2} = \frac{42}{2} = 21 \] ### Step 5: Calculate \(\sum \frac{1}{\alpha}\) Using the relationship: \[ \sum \frac{1}{\alpha} = \frac{\alpha \beta \gamma + \alpha \beta \delta + \alpha \gamma \delta + \beta \gamma \delta}{\alpha \beta \gamma \delta} \] We already have: - \(\alpha \beta \gamma = 21\) - \(\alpha \beta \gamma + 5(\alpha + \beta + \gamma) = \frac{7}{2}\) The product of the roots: \[ \alpha \beta \gamma \delta = \frac{e}{a} = -\frac{-1}{2} = \frac{1}{2} \] ### Step 6: Substitute values into the equation Now substituting: \[ \sum \frac{1}{\alpha} = \frac{21 + \frac{7}{2}}{\frac{1}{2}} = \frac{21 \cdot 2 + 7}{1} = 42 + 7 = 49 \] ### Step 7: Final calculation Now we can compute: \[ \sum \frac{\alpha + 1}{\alpha} = 4 + \sum \frac{1}{\alpha} = 4 + 49 = 53 \] ### Final Answer Thus, the value of \(\sum \frac{\alpha + 1}{\alpha}\) is: \[ \boxed{53} \]
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RESONANCE ENGLISH-EQUATIONS -EXERCISE-1 (PART -1: PRE RMO)
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  3. If roots of equation 2x^(4) - 3x^(3) + 2x^2 - 7x -1 = 0 are alpha, bet...

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  4. If two roots of the equation x^3 - px^2 + qx - r = 0 are equal in magn...

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  20. If one root of sqrt(a-x) + sqrt(b+x) = sqrt(a) + sqrt(b) is 2012, th...

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