1. Introduction to Trigonometric Functions
Honors Precalculus
April 9-10, 2018
Mr. Agnew

2. Essential Question Essential Vocabulary
What is the Unit Circle and how do we use it to evaluate trigonometric functions?
Essential Vocabulary
Unit Circle
Degrees
Radians
Trigonometric Functions

3. The Unit Circle
The Unit Circle is a circle centered at the origin with radius of 1.
All of trigonometry is based on the unit circle.
Trigonometry is the study of angles and the corresponding points on the unit circle.

4. Angles Angle in standard position
One side on positive x axis and vertex at origin
Angles can be positive or negative, and can be larger than 180°.
Angles can be measured in degrees or in radians.

5. Converting Angles Angles can be measured in degrees or radians.
Activity on radian measure
To convert an angle…
From Degrees to Radians:
From Radians to Degrees:

6. Reference Angles
All angles have a reference angle in the first quadrant.
Coterminal angles… all angles have a coterminal angle between
0° and 360° OR 0 and 2π
Examples…

7. The Unit Circle We are going to fill in the values on the unit circle
“Special Angles” on the unit circle
30, 60, and 45, 45, 90
“Special Angles” on unit circle give “special points” on the unit circle.

8. Evaluating Trig Functions
Given a point (x,y) on the unit circle, the value of the 6 trig functions are…

9. Evaluating Trig Functions
When evaluating a trig function…
Find coterminal angle on unit circle
Determine sign of value (All Students Take Calculus)
Find reference angle
Find value
Examples, on & off calc

10. Evaluating Trig Worksheet
Homework: 4/10/18
Evaluating Trig Worksheet