Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int\frac{(x+\sqrt{1+x^2})^{2009}}{\sqrt{1+x^2}}dx$ is equal to :

Options:

$\frac{2(x+\sqrt{1+x^2})^{2009}}{2009}+C$

$\frac{(x+\sqrt{1+x^2})^{2009}}{2009}+C$

$\frac{(\sqrt{1+x^2})^{2009}}{2009}+C$

None of these

Correct Answer:

$\frac{(x+\sqrt{1+x^2})^{2009}}{2009}+C$

Explanation:

Put $x+\sqrt{1+x^2}=t⇒1+\frac{2x}{2\sqrt{1+x^2}}dx=dt⇒\frac{(\sqrt{1+x^2}+x)}{\sqrt{1+x^2}}dx=dt$

$∴I=\int\frac{t^{2009}}{t}dt=\frac{t^{2009}}{2009}+C=\frac{(x+\sqrt{1+x^2})^{2009}}{2009}+C$