Lesson 4

Discover

Try This 1

Use Investigating Trigonometric Ratios and the Unit Circle to answer these questions. Use the angle θ slider to see how the x- and y-coordinates of point P on the unit circle relate to cos θ, sin θ, and tan θ.

1. Choose two points in each quadrant. Fill in a chart similar to the following for each point you choose. Add more rows as needed.
   
   

   Angle θ	Point (x, y)	Quadrant	x	y	cos θ	sin θ	tan θ (as a fraction)	tan θ
   45°	(0.7071, 0.7071)	1	0.7071	0.7071	0.7071	0.7071		1

   
   
   
2. What relationship do you see between the values of x, y, cos θ, sin θ, and tan θ?

 Save your responses in your course folder.

Share 1

With a partner or group, explain why you think the relationships you observed in Try This 1 exist between the values of x, y, cos θ, sin θ, and tan θ.

 If required, place a summary of your discussion in your course folder.