Activity Detail
If you are using a TI-73, TI-83, TI-84 or TI-89, there may be particular math or science applications you will need to download to use certain activities. If you are using TI-Nspire technology, please update your TI-Nspire handheld operating system or computer software to view the latest activities. The latest TI-Nspire operating system was released in June 2009.
Browse by Subject Submit Activity Saved Activities Advanced Search
  


add to saved activities



print this activity
 
Exploring the Unit Circle
 


Activity Overview

In this activity, students explore the properties of a unit circle and its mapping functions.

Before the Activity

  • Select the Cabri Geometry application on the calculator
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 1 - 6 from the attached PDF file for your class

    		•

    		During the Activity

    		Distribute the pages to the class.

    Follow the Activity procedures:
  • Construct a unit circle with origin at (0, 0) and radius of 1 unit
  • Display the equation of the circle
  • Mark a point a (x, y) on the circle in the first quadrant and identify its coordinates
  • Draw a ray from the center of the circle to this point
  • Measure the central angle (angle formed by the constructed ray and the ray that is the positive x-axis)
  • Move the point on the circle and measure the new central angle
  • Repeat for other points on the circle
  • Record the coordinates of the points and the measure of the central angle
  • Plot a graph of angle versus x-coordinate and angle versus y-coordinate
  • Graph the functions sin(x) and cos(x) and compare the graphs
  • Observe that the amplitude of both graphed functions represents the radius of the circle

    		After the Activity

    		Review student results:
  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary

    		Other Downloads




    view standards alignment
    view textbook alignment

    Subject Area:
    Math : Geometry : Circles

    Author:
    Texas Instruments

    Level:
    9-12

    Activity Time:
    60 Minutes

    Device:
    TI-89 / TI-89 Titanium

    Apps:
    Cabri Geometry

    Software:
    TI Connect™

    Accessories:
    TI Connectivity Cable

    Other:
    This is Activity 1 from the EXPLORATIONS Book:
    Discovering Math on the Voyage 200.

    Report an issue with this activity