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
$\int \frac{e^x}{\left(2+e^x\right)\left(e^x+1\right)} d x=$
(where $C$ is $a$ constant of integration.)
MathematicsIndefinite IntegrationMHT CETMHT CET 2022 (07 Aug Shift 1)
Options:
  • A $\frac{e^x+1}{e^x+2}+C$
  • B $\log \left(\frac{e^x+2}{e^x+1}\right)+C$
  • C $\log \left(\frac{e^x+1}{e^x+2}\right)+C$
  • D $\log \left(\frac{e^x}{e^x+2}\right)+C$
Solution:
2661 Upvotes Verified Answer
The correct answer is: $\log \left(\frac{e^x+1}{e^x+2}\right)+C$
$\begin{aligned} & \int \frac{e^x}{\left(2+e^x\right)\left(e^x+1\right)} d x \\ & =\int \frac{d t}{(t+2)(t+1)}=\int\left(\frac{-1}{t+2}+\frac{1}{t+1}\right) d t \\ & =-\log |t+2|+\log |t+1|+c \\ & =\log \left|\frac{t+1}{t+2}\right|+c \\ & =\log \left|\frac{e^x+1}{e^x+2}\right|+c\end{aligned}$

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.