Question

How does amplitude relate to the unit circle?

Answer 1

If you make the circle larger, then there is more difference beeen 'all the way up' and 'all the way down'

Say you are in a Ferris wheel, and we decide that the level of the axis of the wheel is called `0`

Then your maximum height above the axis is one radius above `0`, and your minimum height is radius below `0` You can easily derive the 'amplitude' of a Ferris wheel by taking half de diameter of the wheel.

This height we call amplitude .

In other words: the amplitude is half the diameter (=the radius) of the circle.