Integral Calculus Question 180

Question: $ \int_{{}}^{{}}{[ \log (\log x)+\frac{1}{{{(\log x)}^{2}}} ]}\ dx= $

Options:

A) $ x\log (\log x)+\frac{x}{\log x}+c $

B) $ x\log (\log x)-\frac{x}{\log x}+c $

C) $ x\log (\log x)+\frac{\log x}{x}+c $

D) $ x\log (\log x)-\frac{\log x}{x}+c $

Show Answer

Answer:

Correct Answer: B

Solution:

$ \int_{{}}^{{}}{[ \log (\log x)+\frac{1}{{{(\log x)}^{2}}} ],dx}=\int_{{}}^{{}}{\log (\log x)dx+\int_{{}}^{{}}{\frac{1}{{{(\log x)}^{2}}}}}dx $ $ =x\log (\log x)-\int_{{}}^{{}}{\frac{x}{x\log x},dx+\int_{{}}^{{}}{\frac{1}{{{(\log x)}^{2}}}dx}} $ $ =x\log (\log x)-\frac{x}{\log x}-\int_{{}}^{{}}{\frac{1}{{{(\log x)}^{2}}}dx+\int_{{}}^{{}}{\frac{1}{{{(\log x)}^{2}}}dx}} $ $ =x\log (\log x)-\frac{x}{\log x}+c. $