The purpose
of this applet is to illustrate how the values of a, b, c and k affect
the graph of the cosine function. Use it as follows:

Use the scroll bar to change
the values of a, b, k and c. The graph of the cosine function should
change as these values change. The value of each parameter to the
left of the scroll bar should also be updated. The changes should
happen as follows:

- Changing a will move
the graph up or down by |a| units.
- Changing b will change
the amplitude (thus the range).
- Changing k affects the
period. The period is 2 pi / k.
- Changing c will cause
the graph to be shifted left or right by |c| units.