Integral Calculus Question 340

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

[DSSE 1982]

Options:

A) $ ( x-\frac{x^{3}}{3} )\log x-( x-\frac{x^{3}}{9} )+c $

B) $ ( x-\frac{x^{3}}{3} )\log x+( x-\frac{x^{3}}{9} )+c $

C) $ ( x+\frac{x^{3}}{3} )\log x+( x+\frac{x^{3}}{9} )+c $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

$ \int_{{}}^{{}}{(1-x^{2})\log x,dx}=\int_{{}}^{{}}{\log x,dx}-\int_{{}}^{{}}{x^{2}\log x,dx} $ $ =x(\log x-1)-\frac{x^{3}\log x}{3}+\frac{x^{3}}{9}+c $ $ =( x-\frac{x^{3}}{3} )\log x-( x-\frac{x^{3}}{9} )+c. $