Malorie's blog

8-2



this section deals with graphs with a period change.



To graph, you must know what graphs of sine and cosine look like.

(sorry i don't have pictures like some people . . . DYLAN.)



A graph of sine would go through the origin (0,0)



A graph of cosine will not go through the origin.



*hint: if it is positive, it will go through the y-axsis above 0

if it is negative, it will go through the y-axsis below 0.*





To begin graphing with a period change: y=Acos/sinBx



A) you must find the amplitude and period.



the amplitude is the distance from 0 to the highest point.

A= Amp

the period is how long it take a function to repeat itself.

2Pi/B= Period



B) You must find the points on the graph.

You take the five numbers below and divide by B

1. 0

2. pi/2

3. pi

4. 3pi/2

5. 2pi



C) Sketch the graph





Example:



1) y=4sin4x



amp: 4

period: 2pi/4= pi/2



1. o/ 4= 0

2. pi/2 * 1/4= pi/8

3. pi * 1/4= pi/4

4. 3pi/2 * 1/4=3pi/8

5. 2pi *1/4 =pi/2





since this is sine, the line on the graph will go through 0, and go up to four, then, go down to negative 4, and continously go on.

you will then lable where the graph goes through 0, then when it's at it's highest point, then when it passes the x-axsis, then it's lowest point, and lastly, where it begins to repeat itself at.



(sorry if the graph is hard to explain)




and now you know how to graph with a period change (: