Question

Find the period : $\tan 3x+\cos \frac{5x}{2}$

• A. $2\pi$
• B. $4\pi$
• C. $6\pi$
• D. $8\pi$

Answer 1

Answer: (B)

$4\pi$

Period of $\tan 3x$ is $\frac{\pi }{3}$

and period of $\cos \frac{5x}{2}$ is $\frac{2\pi }{5/2}=\frac{4\pi }{5}$

Hence period of $\tan 3x+\cos \frac{5x}{2}$ is LCM of $\frac{\pi }{3}$ and $\frac{4\pi }{5}$ which is $4\pi$