### Fourier Series Demo

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**

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

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

**Example 3/b>
**
- Return to the settings for Example 1. Set k=7.
- Check
**Show Error**.