# How do we find the period of Sin(3x) + cos(5x)?

The period of sin 3x is $\frac{2 \pi}{3.}$
The period of cos 5x is$\frac{2 \pi}{5}$
Their common period is the least multiple of $\frac{2 \pi}{3} \mathmr{and} \frac{2 \pi}{5}$, that is 2pi.
$\frac{2 \pi}{3} . \left(3\right) = 2 \pi$
$\frac{2 \pi}{5} . \left(5\right) = 2 \pi$