Integral Calculus Question 97

Question: The value of $ \int\limits_1^{e}{\frac{1+x^{2}\ln ,x}{x+x^{2}\ln ,x}dx} $ is

Options:

A) $ e $

B) $ \ln ,(1+e) $

C) $ e+\ln (1+e) $

D) $ e-\ln (1+e) $

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Answer:

Correct Answer: D

Solution:

[d] $ I=\int\limits_1^{e}{( \frac{1}{x}+1 )}dx-\int\limits_1^{e}{\frac{1+\ln x}{1+x\ln x}dx} $ $ ={{[\ln x+x]}_1}^{e}-[\ln (1+x\ln x)]_1^{e} $ $ =e-\ln (1+e) $