In chapter 8 we are learning more to do with graphs. In 8-2, we were taught to find the amplitude, period, and period change which have to do with shifting of graphs.

Amplitude is the distance from 0 to the highest point going vertically on a graph.
Period is how long it take the function (waves) to repeat themselves.

Formulas:
Y=A sin Bx or A cos Bx
A (Absolute value of "A") is the amplitude
2pi/B is the period

In order to graph the period change you must figure out the 5 points.
1. Take the 5 points: 0, pi/2, pi, 3pi/2, and 2pi.
2. Divide each one of these points by B.
*Do not divide by period, remember to take the original B
3.Once you have the 5 points, sketch the graph.

Ex: Find the amplitude, period, and period change of y=-8 sin 4x

First, find amplitude and period.
A=8 P=2pi/4=1/2

Next, to find the 5 points to graph, take orinal 5 points and divide by 4.
1. 0
2. pi
3. 2pi
4. 3pi
5. 4pi