Click on the picture above to watch an animation linking the unit circle to the graphs of sine and cosine.

Write down questions and answers.

http://www.brightstorm.com/math/trigonometry/trigonometric-functions/graphs-of-the-sine-and-cosine-functions/

Click on this link and watch this video. Write down the definition for a periodic function

Sketch 3 different examples of period functions and indicate what their period is.

Watch this video

Use the chart and graph on the next slide to help you take notes. This is the same as what is to the right of the SMART Board.

π 2

π

3π 2

2π

1

-1

Modeling with sine and cosine

Weather patterns

Seasonal fluctuations in demands for surf equipment, swim wear, snow shovels, etc

Employment

Electrical Current

Summarize on your notes

Copy in your notes

Summarize on your notes

Copy in your notes

Here is an example of a real world problem with the solution. Try to follow.

Note: Most textbooks use

f(x)= a sin b(x-c) +d

a= amplitudeb= 2π/b period

c= horizontal shiftd= vertical shift

4.3 sin0.82(t-.37) +7.3a b c d

factor out 0.82 ∴ b=0.82

PUT IN NOTES

Final Interpretation:

I know the last example was challenging. The point was to show you how these functions are used in the real world.