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		 Unit Circle Investigation
  Listed below are two investigations that will allow you to 
      investigate the workings of the unit circle and the relationship between 
      the unit circle and the trigonometric graphs. 
        
        
          
            | Animated display of the 
            relationship between the unit circle and the creation of the 
            trigonometric curves |  
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              Set the MODE to Radian, Parametric (Par), 
              and Simultaneous (Simul). | 
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              Set the WINDOW to:
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             Use the up and down arrows to
 move between the unit circle and
 the trig curve.
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              Enter the equations:
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              Press GRAPH.   The Unit Circle and the Trigonometric graph will be drawn 
              simultaneously.  Trace between the unit circle and the trig 
              curve to see the relationships between the graphs. |  
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              A further exploration can be demonstrated by 
              changing Y2T = cos T  and again tracing between the graphs. |    
        
        
          
            | Investigate the Unit Circle more 
            closely: |  
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              Set the MODE to Degree, Parametric (Par),
              Sequential and clear the equations. | 
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              Set the WINDOW to:
  Note:  The Tstep controls the 
              increment of angle rotation.
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              Enter the equations:
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              Press TRACE and arrow to the right.  The spider will work its way around 
              the unit circle examining the angles as it progresses. | 
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