1. Graphing Trig Functions
Graphing Trig Functions
SAMM
Sections 2.7 and 2.8
Amplitude and Period - Notes

2. Graphing Terminology
Amplitude—The maximum or minimum vertical distance between the graph and the x-axis. Amplitude is always positive because it is a distance.
Period--The number of degrees or radians we must graph before it begins to repeat.

3. Amplitude
Amplitude
Period

4. This number controls the period.
Trig Functions
Trig functions are written in the form of
y = AsinBx or y = AcosBx
y= 5 sin 2x
This number controls the period.
Amplitude

5. Graphing Sine and Cosine
To find the period length —

6. To find the angles to use for graphing –
Find the sum of the beginning and end angles and divide by two.
Repeat step 2 with the beginning and middle angles. Do the same with the middle and end angles.

7. Quick graph of the Cosine function is Max-Zero-Min-Zero-Max
Quick graph of the Sine function is Zero-Max-Zero-Min-Zero
Quick graph of the Cosine function
is Max-Zero-Min-Zero-Max
Sketch a sine or cosine curve
Based on the points graphed.

8. The amplitude is ? The period length is?. Example #1 y= 2sin4x
Answer is 2. Remember, amplitude is always a positive number .
The period length is?.

9. Graph y = 2sin4x

10. The amplitude is ? The period length is?. Example #2 y= -3cos2x
Answer is 3. Remember, amplitude is always a positive number .
The negative means the graph will be flipped when graphed – How does this happen?
The period length is?.

11. Graph y = -3cos2x