Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

Evaluate $\int \frac{(1 + \cos x)}{x + \sin x} dx$.

Options:

$\ln|1 + \cos x| + C$

$\frac{1}{(x + \sin x)^2} + C$

$\ln|x + \sin x| + C$

$x + \sin x + C$

Correct Answer:

$\ln|x + \sin x| + C$

Explanation:

The correct answer is Option (3) → $\ln|x + \sin x| + C$

Consider that,

$I = \int \frac{(1 + \cos x)}{(x + \sin x)} dx$

Let $x + \sin x = t \Rightarrow (1 + \cos x) dx = dt$

$∴I = \int \frac{1}{t} dt = \log |t| + C$

$= \log |(x + \sin x)| + C$