Q. $\int_{0}^{\pi}{\sqrt{\frac{\cos{2x + 1}}{2}}\ dx}$ is equal to
A) 0
B) 2
C) $- 2$
D) None of these
Explanation
(b)
$\int_{0}^{\pi}{\sqrt{\frac{\cos{2x + 1}}{2}}dx = \int_{0}^{\pi}{\sqrt{\cos^{2}x}dx = \int_{0}^{\pi}{|\cos{x|\ dx}}}}$
$= \int_{0}^{\pi/2}{\cos{x\ dx - \int_{\pi/2}^{\pi}{\cos{x\ dx}}}}$
$= 2$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.