Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int\left(1+x-x^{-1}\right) e^{x+x^{-1}} d x$, is equal to

Options:

$x e^{x+x^{-1}}+C$

$-x e^{x+x^{-1}}+C$

$(x+1) e^{x+x^{-1}}+C$

$(x-1) e^{x+x^{-1}}+C$

Correct Answer:

$x e^{x+x^{-1}}+C$

Explanation:

Let $I=\int\left(1+x-x^{-1}\right) e^{x+x^{-1}} d x$. Then,

$I=\int e^{x+x^{-1}} d x+\int x\left(1-\frac{1}{x^2}\right) e^{x+\frac{1}{x}} d x$

$\Rightarrow I=\int e^{x+x^{-1}} d x+x e^{x+\frac{1}{x}}-\int e^{x+x^{-1}} d x+C$

$\Rightarrow I=x e^{x+x^{-1}}+C$