Trigonometric Functions of Quadrantal Angles

1. Trigonometric Functions of Quadrantal Angles Chapter 13.3

2. Quadrantal Angles • The terminal side of a Quadrantal Angle lies on an axis. • Examples: 0◦, 90◦, 180◦, 270◦, 360◦, … any multiple of 90◦

3. Quadrantal Angles • The terminal side of a Quadrantal Angle lies on an axis. • Examples: 0◦, 90◦, 180◦, 270◦, 360◦, … any multiple of 90◦

4. The Unit Circle • Center at the Origin • Radius = 1 We’ll use the unit circle to evaluate the Trig. Functions of Quadrantal Angles…

5. Trig. Functions of Quadrantal Angles • Instead of x- and y-coordinates (x, y), we will think of these as (cosine, sine) & remember r = 1 sin θ = cos θ = tan θ = csc θ = sec θ = cot θ =

6. Trig. Functions of Quadrantal Angles • Instead of x- and y-coordinates (x, y) we think of these as (cosine, sine) sin θ = cos θ = tan θ = csc θ = sec θ = cot θ =

7. sin θ = = = 0 cos θ = = = -1 tan θ = = = 0 θ

8. sin θ = 0; cos -1; tan θ = 0 sin θ = = cos θ = = tan θ = = csc θ = = sec θ = = = -1 cot θ = = = = θ

9. Trig. Functions of Quadrantal Angles • Instead of x- and y-coordinates (x, y), we will think of these as (cosine, sine) & remember r = 1 sin θ = cos θ = tan θ = csc θ = sec θ = cot θ =