1. 7-3 Identities Day 1

2. Identities Identities are like _______________________
We will work on one side only. Usually the HARDER looking side.
If there are fractions ____________________
______________if it helps!

3. Need to remember:

4. Examples

5. Need some hints? Choose harder side. Tossup? Try the left side.
Fractions? ___________________.
__________, if it helps.
One side in many functions/ other side in one? Work on the ______________ side and get it into the only function seen on the other side.

10. Angle Addition/Subtraction
7-4 Formulas
Angle Addition/Subtraction

11. Lets try an experiment? What is ? Is it equal to
This demonstrates that trigonometric functions ____________________________
Imagine

12. The Formulas Based on Geometry and distance Formula

13. The Formulas Based on Geometry and distance Formula

14. What do these formulas do?
Essentially give you the option of
finding the sin/cos of an angle that can be made up of two angles you know. While you don’t know the cos 75 °, you know that 75° is made up of two angles that you know.
Going backwards, and “compressing” an expanded formula into a form you can solve.

15. Examples
Find the following 1.

16. Prove by angle addition formulas.

18. Example
7. Given , and
Find

19. Class Work
Find the following 4. 5. 6.

20. Double Angle Half Angle
7-5 More Formulas
Double Angle
Half Angle

21. Lets derive some formulas:
What is ?
What is

22. Some other versions

23. Example
Evaluate sin 60 using double angles.

24. If and
find 5 13
-12

25. Find b 4 b Θ Θ 2

26. Half Angle Formulas

27. Examples
1. Evaluate sin 15 using half angle.

28. If and find

29. Find