Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int \frac{\left\{x+\sqrt{x^2+1}\right\}^n}{\sqrt{x^2+1}} d x$ is equal to

Options:

$\left\{x+\sqrt{x^2+1}\right\}^n+C$

$\frac{1}{n}\left\{x+\sqrt{x^2+1}\right\}^n+C$

$\frac{1}{n+1}\left\{x+\sqrt{x^2+1}\right\}^{n+1}+C$

none of these

Correct Answer:

$\frac{1}{n}\left\{x+\sqrt{x^2+1}\right\}^n+C$

Explanation:

Let

$I=\int \frac{\left\{x+\sqrt{x^2+1}\right\}^n}{\sqrt{x^2+1}} d x$

$\Rightarrow I=\int\left\{x+\sqrt{x^2+1}\right\}^{n-1} \times \frac{x+\sqrt{x^2+1}}{\sqrt{x^2+1}} d x$

$\Rightarrow I=\int\left\{x+\sqrt{x^2+1}\right\}^{n-1} d\left(x+\sqrt{x^2+1}\right)$

$\Rightarrow I=\frac{1}{n}\left(x+\sqrt{x^2+1}\right)^n+C$