I cannot ask a question in the comment section therefore I decided to add my question here.
The website provided by Yicheng Ye somehow gives something and I believe people who know this stuff understand all of it but I still find it confusing. I don't understand how to work out the fundamental frequency or minimum period.
I tried my own workaround but I am not sure if I am right. Please correct me if I am wrong. Thanks. Fundamental frequency:
$\omega_0n=2\pi\frac{M}{N}n$, ..... dividing by n gives
$\omega_0=2\pi\frac{M}{N}$
To calculate minimum period, I have rearranged the formula $\frac{\omega_0}{2\pi{}M}=\frac{1}{N}$ and then got the answer:
$N=\frac{2\pi{}M}{\omega_0}$
Which means that $N$ is a minimum period. I don't feel if this is correct. Perhaps I don't because cannot really understand what $M$ represents here or what it does correspond to. I will be grateful for explanation. Cheers!