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Let inte^(x).x^(2)dx=f(x)e^(x)+C (where,...

Let `inte^(x).x^(2)dx=f(x)e^(x)+C` (where, C is the constant of integration). The range of f(x) as `x in R` is `[a, oo)`. The value of `(a)/(4)` is

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To solve the problem, we need to analyze the given integral and find the function \( f(x) \) such that the range of \( f(x) \) is \([a, \infty)\). We will then determine the value of \( \frac{a}{4} \). ### Step-by-Step Solution: 1. **Start with the given integral**: \[ \int e^x x^2 \, dx = f(x) e^x + C \] 2. **Use integration by parts**: We will apply integration by parts where we let: - \( u = x^2 \) and \( dv = e^x \, dx \) - Then, \( du = 2x \, dx \) and \( v = e^x \) Using the integration by parts formula \( \int u \, dv = uv - \int v \, du \): \[ \int e^x x^2 \, dx = x^2 e^x - \int e^x (2x) \, dx \] 3. **Apply integration by parts again**: Now we need to integrate \( \int e^x (2x) \, dx \): - Let \( u = 2x \) and \( dv = e^x \, dx \) - Then, \( du = 2 \, dx \) and \( v = e^x \) Applying integration by parts again: \[ \int e^x (2x) \, dx = 2x e^x - \int 2 e^x \, dx = 2x e^x - 2 e^x \] 4. **Combine the results**: Substitute back into the equation: \[ \int e^x x^2 \, dx = x^2 e^x - (2x e^x - 2 e^x) = x^2 e^x - 2x e^x + 2 e^x \] Simplifying gives: \[ \int e^x x^2 \, dx = e^x (x^2 - 2x + 2) + C \] 5. **Identify \( f(x) \)**: From the integral, we can identify: \[ f(x) = x^2 - 2x + 2 \] 6. **Determine the range of \( f(x) \)**: The function \( f(x) = x^2 - 2x + 2 \) is a quadratic function. To find its minimum value, we can complete the square: \[ f(x) = (x - 1)^2 + 1 \] The minimum value occurs at \( x = 1 \): \[ f(1) = (1 - 1)^2 + 1 = 1 \] Therefore, the range of \( f(x) \) is \([1, \infty)\). 7. **Find \( a \)**: From the range \([a, \infty)\), we have \( a = 1 \). 8. **Calculate \( \frac{a}{4} \)**: \[ \frac{a}{4} = \frac{1}{4} = 0.25 \] ### Final Answer: The value of \( \frac{a}{4} \) is \( 0.25 \).
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