Deriving the cosine graph from the unit circle

[b]Important convention:[/b] Angles are always measured anticlockwise from the positive x-axis.[br][br]Drag the angle slider along to see how the cosine graph is generated. Consider how this follows on from the first applet. Why is it useful to use the unit circle (radius 1)?[br][br]What is the [u]amplitude[/u] of the cosine graph? How can you tell by looking at the graph/unit circle?[br]What is the [u]period[/u] of the cosine graph? How can you tell by looking at the graph/unit circle?

Information: Deriving the cosine graph from the unit circle