Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int\frac{\log_e x}{(1+ \log_e x)^2}dx$ is equal to

Options:

$\frac{1}{(1+ \log_e x)^2}+C$, where C is constant of integration

$\frac{x}{1+ \log_e x}+C$, where C is constant of integration

$\frac{x}{(1+ \log_e x)^2}+C$, where C is constant of integration

$\frac{1}{1+ \log_e x}+C$, where C is constant of integration

Correct Answer:

$\frac{x}{1+ \log_e x}+C$, where C is constant of integration

Explanation:

The correct answer is Option (2) → $\frac{x}{1+ \log_e x}+C$, where C is constant of integration

$\int \frac{\log_e x}{(1+\log_e x)^2}\,dx$

Note: $\frac{d}{dx}\!\left(\frac{x}{1+\log_e x}\right)=\frac{(1+\log_e x)-1}{(1+\log_e x)^2}=\frac{\log_e x}{(1+\log_e x)^2}$

$\Rightarrow \int \frac{\log_e x}{(1+\log_e x)^2}\,dx=\frac{x}{1+\log_e x}+C$

$\frac{x}{1+\log_e x}+C$