If you get a message "need java2 for this applet" then you
can use the Java 1 version of this applet
(but you won't get sound). If you don't have Java 2 I recommend
you go get the Java plug-in.
This java applet demonstrates
Fourier series,
which is a method of expressing an arbitrary periodic function as
a sum of cosine terms. In other words, Fourier series can be used to express a
function in terms of the frequencies (harmonics) it is composed of.
To select a function, you may press one of the following buttons:
Sine, Triangle, Sawtooth, Square, and Noise. The function is
displayed in white, with the Fourier series approximation in red.
You can edit the function directly by clicking on it.
