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Statement-1: If f(x)=int(1)^(x) (log(e ...

Statement-1: If `f(x)=int_(1)^(x) (log_(e )t)/(1+t+t^(2))dt`, then
`f(x)=f((1)/(x))`for all `x gt 0`.
Statement-2:If f(x)`=int_(1)^(x) (log_(e )t)/(1+t)dt`, then `f(x)+f((1)/(x))=((log_(e )x)^(2))/(2)`

A

Statement-1 is true, Statement-2 is True,Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is True, Statement-2 is not a correct explanation for Statement-1.

C

Statement-1 is True, Statement-2 is False.

D

Statement-1 is False, Statement-2 is True.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem, we need to analyze both statements separately. ### Statement 1: We need to prove that if \( f(x) = \int_{1}^{x} \frac{\log t}{1+t+t^2} dt \), then \( f(x) = f\left(\frac{1}{x}\right) \) for all \( x > 0 \). 1. **Define \( f(x) \)**: \[ f(x) = \int_{1}^{x} \frac{\log t}{1+t+t^2} dt \] 2. **Change of variable**: Let \( t = \frac{1}{u} \). Then, \( dt = -\frac{1}{u^2} du \). - When \( t = 1 \), \( u = 1 \). - When \( t = x \), \( u = \frac{1}{x} \). Thus, we have: \[ f\left(\frac{1}{x}\right) = \int_{1}^{\frac{1}{x}} \frac{\log\left(\frac{1}{u}\right)}{1 + \frac{1}{u} + \left(\frac{1}{u}\right)^2} \left(-\frac{1}{u^2}\right) du \] 3. **Simplifying the integral**: \[ = \int_{1}^{\frac{1}{x}} \frac{-\log u}{1 + \frac{1}{u} + \frac{1}{u^2}} \cdot \left(-\frac{1}{u^2}\right) du \] \[ = \int_{1}^{\frac{1}{x}} \frac{\log u}{\frac{u^2 + u + 1}{u^2}} du = \int_{1}^{\frac{1}{x}} \frac{u^2 \log u}{u^2 + u + 1} du \] 4. **Changing limits**: \[ = \int_{\frac{1}{x}}^{1} \frac{u^2 \log u}{u^2 + u + 1} du \] By changing the limits, we can rewrite this as: \[ = -\int_{1}^{\frac{1}{x}} \frac{u^2 \log u}{u^2 + u + 1} du \] 5. **Combining both integrals**: \[ f(x) + f\left(\frac{1}{x}\right) = \int_{1}^{x} \frac{\log t}{1+t+t^2} dt + \int_{1}^{\frac{1}{x}} \frac{\log u}{1+u+u^2} du \] This shows that \( f(x) = f\left(\frac{1}{x}\right) \). ### Conclusion for Statement 1: Thus, Statement 1 is true. --- ### Statement 2: We need to prove that if \( f(x) = \int_{1}^{x} \frac{\log t}{1+t} dt \), then \( f(x) + f\left(\frac{1}{x}\right) = \frac{(\log x)^2}{2} \). 1. **Define \( f(x) \)**: \[ f(x) = \int_{1}^{x} \frac{\log t}{1+t} dt \] 2. **Change of variable**: Let \( t = \frac{1}{u} \). Then, \( dt = -\frac{1}{u^2} du \). - When \( t = 1 \), \( u = 1 \). - When \( t = x \), \( u = \frac{1}{x} \). Thus: \[ f\left(\frac{1}{x}\right) = \int_{1}^{\frac{1}{x}} \frac{\log\left(\frac{1}{u}\right)}{1+\frac{1}{u}} \left(-\frac{1}{u^2}\right) du \] \[ = \int_{1}^{\frac{1}{x}} \frac{-\log u}{\frac{1+u}{u}} \cdot \left(-\frac{1}{u^2}\right) du \] \[ = \int_{1}^{\frac{1}{x}} \frac{u \log u}{1+u} du \] 3. **Combining both integrals**: \[ f(x) + f\left(\frac{1}{x}\right) = \int_{1}^{x} \frac{\log t}{1+t} dt + \int_{1}^{\frac{1}{x}} \frac{u \log u}{1+u} du \] 4. **Using properties of logarithms**: \[ = \int_{1}^{x} \frac{\log t}{1+t} dt + \int_{1}^{x} \frac{\log\left(\frac{1}{t}\right)}{1+\frac{1}{t}} dt \] \[ = \int_{1}^{x} \frac{\log t - \log t}{1+t} dt = \int_{1}^{x} \frac{\log t}{1+t} dt + \int_{1}^{x} \frac{-\log t}{1+t} dt \] 5. **Final result**: \[ f(x) + f\left(\frac{1}{x}\right) = \frac{(\log x)^2}{2} \] ### Conclusion for Statement 2: Thus, Statement 2 is also true. ---

To solve the given problem, we need to analyze both statements separately. ### Statement 1: We need to prove that if \( f(x) = \int_{1}^{x} \frac{\log t}{1+t+t^2} dt \), then \( f(x) = f\left(\frac{1}{x}\right) \) for all \( x > 0 \). 1. **Define \( f(x) \)**: \[ f(x) = \int_{1}^{x} \frac{\log t}{1+t+t^2} dt ...
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