Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

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

Options:

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

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

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

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

Correct Answer:

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

Explanation:

Let

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

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

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

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

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