Integral Calculus Question 354

Question: $ \int{x^{3}\log xdx=} $

[Karnataka CET 2002]

Options:

A) $ \frac{x^{4}\log x}{4}+c $

B) $ \frac{1}{16}[4x^{4}\log x-x^{4}]+c $

C) $ \frac{1}{8}[x^{4}\log x-4x^{2}]+c $

D) $ \frac{1}{16}[4x^{4}\log x+x^{4}]+c $

Show Answer

Answer:

Correct Answer: B

Solution:

$ I=\int{x^{3}\log x,dx} $ $ =\frac{x^{4}}{4}\log x-\int{\frac{x^{4}}{4}\frac{1}{x}dx+c} $ $ =\frac{x^{4}}{4}\log x-\int{\frac{x^{3}}{4}dx,=,\frac{x^{4}}{4}\log x-\frac{x^{4}}{16}+c} $ $ =\frac{1}{16}[4x^{4}\log x-x^{4}]+c $ .