Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
$\int \frac{\log x d x}{x^3}=$
MathematicsIndefinite IntegrationJEE Main
Options:
  • A $\frac{1}{4 x^2}(2 \log x-1)+c$
  • B $-\frac{1}{4 x^2}(2 \log x+1)+c$
  • C $\frac{1}{4 x^2}(2 \log x+1)+c$
  • D $\frac{1}{4 x^2}(1-2 \log x)+c$
Solution:
1582 Upvotes Verified Answer
The correct answer is: $-\frac{1}{4 x^2}(2 \log x+1)+c$
$\begin{aligned} & \int \frac{\log x}{x^3} d x=\int x^{-3} \log x d x \\ & =-\frac{\log x}{2 x^2}+\int \frac{1}{x} \cdot \frac{1}{2 x^2}+c=-\frac{\log x}{2 x^2}+\frac{1}{2} \cdot \frac{x^{-2}}{-2}+c \\ & =-\frac{\log x}{2 x^2}-\frac{1}{4 x^2}+c=-\frac{1}{4 x^2}(2 \log x+1)+c \\ & \end{aligned}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.