1. Solving for Exact Trigonometric Values Using the Unit Circle
15 April 2011

2. Reference Angles
Reference angles make it easier to find exact values of trig functions in the unit circle

3. Reference Angles, cont.
Always

4. Solving for Reference Angles
Step 1: _____________________________ _________________ (Remember, coterminal angles are positive and less than 2π.)
Step 2: _____________________________ (if less than 2π) ______________________ (if greater than 360° or 2π)
Step 3: _____________________________ ____________
This is the reference angle!!!!

5. Example:

6. Example:

7. Example:

8. Your Turn:

9. Your Turn:

10. Your Turn:

11. Your Turn:

12. Your Turn:

13. Solving for Exact Trig Values
Step 1: ____________________________ (Note the quadrant)
Step 2: ________________________________
Step 3: ________________________________ _____________________(Make sure the signs match the quadrant!)
Step 5: ________________________________
Step 6: ___________________ the denominator if necessary

14. Example:
Reference Angle:
Special Triangle:

15. Example:
Coordinates:
Tangent:
Sine:
Cosine:

16. Example:
Reference Angle:
Special Triangle:

17. Example:
Coordinates:
Tangent:
Sine:
Cosine:

18. Example:
Reference Angle:
Special Triangle:

19. Example:
Coordinates:
Tangent:
Sine:
Cosine: