Integral Calculus Question 438

Question: $ \int_{{}}^{{}}{\frac{dx}{x\sqrt{1-{{(\log x)}^{2}}}}=} $

Options:

A) $ {{\cos }^{-1}}(\log x)+c $

B) $ x\log (1-x^{2})+c $

C) $ {{\sin }^{-1}}(\log x)+c $

D) $ \frac{1}{2}{{\cos }^{-1}}(\log x)+c $

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Answer:

Correct Answer: C

Solution:

Put $ \log x=t\Rightarrow \frac{1}{x},dx=dt, $ then it reduces to $ \int_{{}}^{{}}{\frac{dt}{\sqrt{1-t^{2}}}={{\sin }^{-1}}t={{\sin }^{-1}}(\log x)+c.} $