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If `alpha` and `beta` are the zeros of the polynomial `f(x) = 4x^2 - 5x +1`, find a quadratic polynomial whose zeros are `alpha^(2)/beta` and `beta^(2)/alpha`

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To find a quadratic polynomial whose zeros are \(\frac{\alpha^2}{\beta}\) and \(\frac{\beta^2}{\alpha}\), we start from the given polynomial \(f(x) = 4x^2 - 5x + 1\). Here are the steps to solve the problem: ### Step 1: Identify the coefficients of the polynomial The polynomial is given as: \[ f(x) = 4x^2 - 5x + 1 \] From this, we can identify: - \(a = 4\) - \(b = -5\) - \(c = 1\) ### Step 2: Calculate the sum and product of the roots \(\alpha\) and \(\beta\) Using Vieta's formulas: - The sum of the roots \(\alpha + \beta = -\frac{b}{a} = -\frac{-5}{4} = \frac{5}{4}\) - The product of the roots \(\alpha \beta = \frac{c}{a} = \frac{1}{4}\) ### Step 3: Find the sum of the new roots \(\frac{\alpha^2}{\beta} + \frac{\beta^2}{\alpha}\) We can rewrite the sum of the new roots as: \[ \frac{\alpha^2}{\beta} + \frac{\beta^2}{\alpha} = \frac{\alpha^3 + \beta^3}{\alpha \beta} \] Using the identity for the sum of cubes: \[ \alpha^3 + \beta^3 = (\alpha + \beta)(\alpha^2 - \alpha\beta + \beta^2) \] We also know: \[ \alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta = \left(\frac{5}{4}\right)^2 - 2 \cdot \frac{1}{4} = \frac{25}{16} - \frac{2}{4} = \frac{25}{16} - \frac{8}{16} = \frac{17}{16} \] Thus, \[ \alpha^3 + \beta^3 = \left(\frac{5}{4}\right)\left(\frac{17}{16} - \frac{1}{4}\right) = \left(\frac{5}{4}\right)\left(\frac{17}{16} - \frac{4}{16}\right) = \left(\frac{5}{4}\right)\left(\frac{13}{16}\right) = \frac{65}{64} \] Now substituting back: \[ \frac{\alpha^2}{\beta} + \frac{\beta^2}{\alpha} = \frac{\frac{65}{64}}{\frac{1}{4}} = \frac{65}{64} \cdot 4 = \frac{65}{16} \] ### Step 4: Calculate the product of the new roots \(\frac{\alpha^2}{\beta} \cdot \frac{\beta^2}{\alpha}\) This can be simplified as: \[ \frac{\alpha^2}{\beta} \cdot \frac{\beta^2}{\alpha} = \frac{\alpha^2 \beta^2}{\alpha \beta} = \alpha \beta \] We already found \(\alpha \beta = \frac{1}{4}\). ### Step 5: Form the new quadratic polynomial Using the sum and product of the new roots, we can write the new quadratic polynomial: \[ g(x) = x^2 - \left(\frac{65}{16}\right)x + \frac{1}{4} \] ### Step 6: Clear the fractions To eliminate the fractions, multiply the entire equation by 16: \[ 16g(x) = 16x^2 - 65x + 4 \] Thus, the required quadratic polynomial is: \[ g(x) = 16x^2 - 65x + 4 \] ### Final Answer: The quadratic polynomial whose zeros are \(\frac{\alpha^2}{\beta}\) and \(\frac{\beta^2}{\alpha}\) is: \[ \boxed{16x^2 - 65x + 4} \]
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