Integral Calculus Question 214

Question: $ \int_{{}}^{{}}{\frac{x^{3}-x-2}{(1-x^{2})}\ dx=} $

[AI CBSE 1985]

Options:

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

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

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

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

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Answer:

Correct Answer: D

Solution:

$ \int_{{}}^{{}}{\frac{x^{3}-x-2}{(1-x^{2})},dx}=\int_{{}}^{{}}{\frac{-x(1-x^{2})}{(1-x^{2})},dx-\int_{{}}^{{}}{\frac{2}{1-x^{2}},dx}} $ $ =-\int_{{}}^{{}}{x,dx}-2\int_{{}}^{{}}{\frac{1}{1-x^{2}},dx=\frac{-x^{2}}{2}+\log ( \frac{x-1}{x+1} )+c.} $