Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

$\int\limits_{0}^{2π}e^{x/2}\sin(\frac{x}{2}+\frac{π}{4})dx=$

Options:

$2π$

$e^π$

0

$2\sqrt{2}$

Correct Answer:

0

Explanation:

We have,

$I=\int\limits_{0}^{2π}e^{x/2}\sin(\frac{x}{2}+\frac{π}{4})dx$

$⇒I=2\int\limits_{0}^{π}e^{t}\sin(\frac{π}{4}+t)dt$, where $x=2t$

$⇒I=\frac{2}{\sqrt{2}}\int\limits_{0}^{π}e^t(\sin t+\cos t)dt=\sqrt{2}\left[e^t\,\sin t\right]_{0}^{π}=\sqrt{2}×0=0$