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"Let " f(x)=int x^(sinx)(1+xcosx*In x+si...

`"Let " f(x)=int x^(sinx)(1+xcosx*In x+sinx)dx " and " f((pi)/(2))=(pi^(2))/(4). " Then the value of " cos f(pi) " is"- .`

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To solve the problem step by step, we will analyze the function \( f(x) \) given by the integral: \[ f(x) = \int x^{\sin x} (1 + x \cos x \ln x + \sin x) \, dx \] ### Step 1: Identify the integral We start with the integral expression for \( f(x) \): \[ f(x) = \int x^{\sin x} (1 + x \cos x \ln x + \sin x) \, dx \] ### Step 2: Simplify the integral Notice that the integrand can be expressed in a more manageable form. We can rewrite the first part of the integrand: \[ f(x) = \int x^{\sin x} \, dx + \int x^{\sin x} (x \cos x \ln x + \sin x) \, dx \] ### Step 3: Use substitution Let \( F(x) = x^{\sin x} \). Then, we can differentiate \( F(x) \): \[ F'(x) = e^{\sin x \ln x} \left( \sin x \cdot \frac{1}{x} + \ln x \cdot \cos x \right) \] ### Step 4: Integrate by parts The integral can be expressed as: \[ f(x) = \int F'(x) \, dx \] Using integration by parts, we can express \( f(x) \) in terms of \( F(x) \): \[ f(x) = x F(x) - \int x F'(x) \, dx \] ### Step 5: Evaluate \( f\left(\frac{\pi}{2}\right) \) We know from the problem statement that: \[ f\left(\frac{\pi}{2}\right) = \frac{\pi^2}{4} \] Substituting \( x = \frac{\pi}{2} \): \[ f\left(\frac{\pi}{2}\right) = \frac{\pi}{2} \left(\frac{\pi}{2}\right)^{\sin\left(\frac{\pi}{2}\right)} + C = \frac{\pi}{2} \cdot \frac{\pi}{2} + C = \frac{\pi^2}{4} + C \] This gives us \( C = 0 \). ### Step 6: Calculate \( f(\pi) \) Now we need to find \( f(\pi) \): \[ f(\pi) = \pi \cdot \pi^{\sin(\pi)} + C \] Since \( \sin(\pi) = 0 \): \[ f(\pi) = \pi \cdot \pi^0 + 0 = \pi \] ### Step 7: Find \( \cos(f(\pi)) \) Now we calculate \( \cos(f(\pi)) \): \[ \cos(f(\pi)) = \cos(\pi) = -1 \] ### Final Answer Thus, the value of \( \cos(f(\pi)) \) is: \[ \boxed{-1} \]

To solve the problem step by step, we will analyze the function \( f(x) \) given by the integral: \[ f(x) = \int x^{\sin x} (1 + x \cos x \ln x + \sin x) \, dx \] ### Step 1: Identify the integral We start with the integral expression for \( f(x) \): ...
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