Integral Calculus Question 327

Question: $ \int_{{}}^{{}}{\frac{1}{{\log_{x}}e}dx=} $

[MP PET 1994]

Options:

A) $ \log {\log_{x}}e+c $

B) $ \frac{1}{{{({\log_{x}}e)}^{2}}}+c $

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

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

$ \int_{{}}^{{}}{\frac{1}{{\log_{x}}e},dx=\int_{{}}^{{}}{{\log_{e}}x,dx}=x\log x-x+c} $ $ =x({\log_{e}}x-{\log_{e}}e)+c=x{\log_{e}}( \frac{x}{e} )+c. $