

A nice related bookmark I have saved. There’s also interactive pert with a slider where you can draw a wave and then add more and more sinusoids to get closer and closer. And of course the square wave, with infinite sinusoids (theoretically).
https://www.jezzamon.com/fourier/












Yeah, 10/10 or 01/10 which is 2/2 and 1/2 in decimal respectively.