## Wednesday, February 3, 2010

### Periodic Functions

In this one the good part starts around 0:08, then again in the final seconds -

Plan - show one clip or both. What are we looking at here? What are the features of the motion? What words would you use to describe it? How might you compare one swimmer's kick with another's? What attributes might you try changing to improve a kick? How does the sun's path differ at other times of the year? At other latitudes? How is it the same? Generally keep poking at it until we describe it as periodic, and mention synonyms for amplitude and frequency. Proceed as usual.

Later in the unit, project a still of the kick trail, and write an equation for it.

If anyone's got other clips of periodic motion bookmarked or favorited, I'd love to see them.

Terry Kaminski said...

Thanks for sharing these video clips. Videos are always a great intro to any topic. The grab the students attention and promote lots of discussion. I am sure glad you are a part of my PLN.

Great videos. I have several time lapse videos I took (only uploaded one so far to youtube - http://www.youtube.com/watch?v=2o7HGRd8T9Y) of a fast growing plant showing some interesting periodic motion. I'd love to see it or some of the other ones used for mathematics. Let me know and I'll upload some more. Love your blog, by the way.

Mtgchic said...

These photos were mentioned in Wired this month, although they are probably above Alg II w/ Trig (since some of them were above my head), but a pretty thing to look at. Go here: http://nikkigraziano.com/index.html then click on "photographer" then click on the picture to advance to the next pic.

G. Bautista said...

Hi Kate. I have created a tutorial on how to trace the graph of trigonometric function, i think it will also be a good help in discussing periodic functions. You may want to check it out.

http://math4allages.wordpress.com/2010/02/10/geogebratutorial8/

Julia Tsygan said...

I found this, too, and will use it for a modeling activity right after I've shown the never ending sun movie clip.
http://img128.imageshack.us/img128/9614/panaramafollowingthesunxy2.jpg