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Let f(x) is a polynomial function and f(...

Let f(x) is a polynomial function and `f(alpha))^(2) + f'(alpha))^(2) = 0`, then find `lim_(x rarr alpha) (f(x))/(f'(x))[(f'(x))/(f(x))]`, where [.] denotes greatest integer function, is........

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To solve the problem, we start with the given condition: 1. **Given Condition**: \[ f(\alpha)^2 + f'(\alpha)^2 = 0 \] Since both \( f(\alpha)^2 \) and \( f'(\alpha)^2 \) are non-negative, the only way their sum can equal zero is if both terms are zero: \[ f(\alpha) = 0 \quad \text{and} \quad f'(\alpha) = 0 \] 2. **Roots of the Polynomial**: Since \( f(\alpha) = 0 \) and \( f'(\alpha) = 0 \), we can conclude that \( \alpha \) is a double root of the polynomial \( f(x) \). Thus, we can express \( f(x) \) as: \[ f(x) = (x - \alpha)^2 g(x) \] where \( g(x) \) is some polynomial function. 3. **Finding the Derivative**: We differentiate \( f(x) \): \[ f'(x) = 2(x - \alpha)g(x) + (x - \alpha)^2 g'(x) \] 4. **Evaluating the Limit**: We need to find: \[ \lim_{x \to \alpha} \frac{f(x)}{f'(x)} \left\lfloor \frac{f'(x)}{f(x)} \right\rfloor \] 5. **Calculating \( \frac{f(x)}{f'(x)} \)**: Substituting \( f(x) \) and \( f'(x) \): \[ f(x) = (x - \alpha)^2 g(x) \] \[ f'(\alpha) = 2(x - \alpha)g(x) + (x - \alpha)^2 g'(\alpha) \] At \( x = \alpha \): \[ f'(\alpha) = 0 \quad \text{(since \( f'(\alpha) = 0 \))} \] Therefore, we can rewrite: \[ f'(x) \approx 2(x - \alpha)g(\alpha) \quad \text{(as \( x \to \alpha \))} \] Thus, \[ \frac{f(x)}{f'(x)} = \frac{(x - \alpha)^2 g(x)}{2(x - \alpha)g(\alpha)} = \frac{(x - \alpha) g(x)}{2g(\alpha)} \] 6. **Taking the Limit**: As \( x \to \alpha \): \[ \lim_{x \to \alpha} \frac{(x - \alpha) g(x)}{2g(\alpha)} = \frac{0 \cdot g(\alpha)}{2g(\alpha)} = 0 \] 7. **Calculating \( \frac{f'(x)}{f(x)} \)**: We have: \[ \frac{f'(x)}{f(x)} = \frac{2(x - \alpha)g(x) + (x - \alpha)^2 g'(x)}{(x - \alpha)^2 g(x)} = \frac{2}{x - \alpha} + \frac{g'(x)}{g(x)} \] As \( x \to \alpha \), \( \frac{2}{x - \alpha} \to \infty \) and \( \frac{g'(x)}{g(x)} \) approaches a finite limit. 8. **Final Limit Calculation**: Since \( \frac{f'(x)}{f(x)} \to \infty \), the greatest integer function \( \left\lfloor \frac{f'(x)}{f(x)} \right\rfloor \) approaches infinity. Therefore: \[ \lim_{x \to \alpha} \frac{f(x)}{f'(x)} \left\lfloor \frac{f'(x)}{f(x)} \right\rfloor = 0 \cdot \infty = 0 \] Thus, the final answer is: \[ \boxed{1} \]
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