Q. $\int_{1}^{3}\frac{\cos{(\log{x)}}\ }{x}\ dx$ is equal to
A) 1
B) $\cos{(\log{3)}}$
C) $\sin{(\log{3)}}$
D) $\frac{\pi}{4}$
Explanation
(c)
$\int_{1}^{3}\frac{cos(\log{x)}}{x}dx = \lbrack sin(\log{x)\left. \ \ \right\rbrack_{1}^{3}}$
$= sin(\log{3) - sin(\log{1) = sin(\log{3)}}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.