Education Technology

# Activities

• ##### Subject Area

• Math: Precalculus: Trigonometry (Triangle and Circular Functions)

9-12
College

2 Hours

• ##### Device
• TI-83
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition
• TI-Navigator™
• ##### Software

TI InterActive!™

• ##### Accessories

Sensor - Microphone

• ##### Other Materials
A Set of Tuning forks with Notes Marked on them
A Set of unknown Tuning Forks (if you want, it can be done without these)

## "The Sound of Music"

#### Activity Overview

This activity will use tuning forks and the CBR™ to gather sound wave data for students to use to write Sine (or Cosine) functions for. In this activity we study waves of known musical notes for before studying waves of unknown musical notes. I have found this is a good end of the unit activity for the circular functions unit, although, it could also be used as an introductory unit with some modifications.

#### Before the Activity

We will have done a unit on circular functions. This activity is designed to be a wrap up of the circular functions unit. Please see the attached detailed lesson plan for more information.

#### During the Activity

During the data collection and the group work, be sure to walk around the room and to monitor students' progress.
Some groups will finish quickly, while others will need more time.
If a group finishes way ahead of the others, give them another note and then there will be three functions for other notes.
This gives more to talk about.
As mention in the attached plans, it is important to have two groups, find the function for each note.
I usually give them different data from the same tuning fork.
By doing this the issue of accuracy of their models comes up a lot in the follow up discussion.

#### After the Activity

After students' have put their results on the board, a class discussion about the functions and their accuracy should follow.
Be prepared for a good discussion and lots of questions.
See the attached project for more information on the follow up activities.