1. Given A unit circle with radius = 1, center point at (0,0)
Notes: 5-3 (part 1)
Given
A unit circle with radius = 1, center point at (0,0) 1
(x, y)
sin θ =
cos θ =
tan θ =
Form a right triangle with the x-axis.

2. csc θ =
sec θ =
cot θ =
sin θ = y
cos θ = x
tan θ =

3. Some trig ratios will be negative if the reference angle is in Quadrant II, III, or IV
Quadrant II values
sinθ =
cosθ =
tanθ =

4. Special angles that are located on the axes:
examples
a. cos 90° =
b. tan 270° =
c. sin 180° =
d. cos 0° =

5. (from yesterday) radius 45° 60° 45° 30°
radius
45°
60°
30°
45°

6. 8. Use the unit circle to find the six trig functions for 225°