Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int \frac{e^x(1+x)}{\cos ^2\left(x e^x\right)} d x$ is equal to:

Options:

$\cot \left(e^x\right)+c$, where c is a constant

$\tan \left(x e^x\right)+c$, where c is a constant

$\cot \left(x e^{x}\right)+c$, where c is a constant

$\tan \left\{e^x(1+x)\right\}+c$, where c is a constant

Correct Answer:

$\tan \left(x e^x\right)+c$, where c is a constant

Explanation:

The correct answer is Option (2) → $\tan \left(x e^x\right)+c$, where c is a constant

$I=\int\frac{e^x(1+x)}{\cos^2(xe^x)}dx$

let $y=xe^x$

$dy=e^x(1+x)dx$

$⇒I=\int\sec^2ydy=\tan y+c$

$=\tan(xe^x)+c$