Fourer Series Demo shows how any periodic signal can be approximated as a sum of sinusoids. It allows you to choose from several input signals and creates an approximation to the signal you choose. You can select how many cosine terms to use in the approximation.

Do This:
Example 1

1. Select Signal Type as Square.
2. Set the Signal Period to 20.
3. Set the Number of Fourier Coefficients to 3.
4. Adjust the number of coefficients to 7 and 17.

Example 2

1. Select Triangle and number of coefficients of 3.
2. Why does the squarewave require so many more coefficients to fit?

Example 3/b>

1. Return to the settings for Example 1. Set k=7.
2. Check Show Error.