1. Objective: Use pythagorean identities.
Warm Up
Fill in the blanks.
a. If , then __________and ________.
b. If , then =_________and =______.
c. If and , then __________.

2. 2.
Find a positive and a negative coterminal angles of 60 degrees.
Find sine, cosine and tangent of the three angles.
c. Based on your observations. What is your conjecture?

3. Pythagorean Identities

4. Example 1 Given that and . Find the value of using a trig identity.

5. Example 2 If ; . Find and .

6. Example 3 Find and . If .

7. Example 4
Find the value using identities. a. b.

8. Example 5
Find (Use calculator).
cos 0.3
sec 0.3 c. d.

9. Assignment: Pg 487 #29-38; 61-70

10. HW CHECK
Pg. 498 #5
Pg. 486# 7, 8, 10
Pg #20,24
Collecting: Review Sheet 4.1