Integral Calculus Question 207

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

[Roorkee 1977]

Options:

A) $ {{(1+\log x)}^{3}}+c $

B) $ 3{{(1+\log x)}^{3}}+c $

C) $ \frac{1}{3}{{(1+\log x)}^{3}}+c $

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

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