The idea of a Fourier series: By adding infinite sine (and or cosine) waves we can make other functions, even if they are a bit weird. Left / Right arrow key to change the Series Term and watch the sine wave change to other functions. Space to end.
This project is based on a tutorial from "Math is Fun": https://www.mathsisfun.com/calculus/fourier-series.html "Math is Fun" make the idea so easy to understand.