Lesson 47: Unit Circle Continued

Presidential Trivia

Unit Circle Quiz

Proof of how coordinates are generated for the family

Proof of coordinates for the family of angles See if you can prove this using the

Pythagorean theorem.

This president was more famous for his unique experimentation with facial hair than for anything he did while in office. Chester A.

Arthur

Develop the family of coordinates. Can use the 30-60-90 triangle again.

Helpful Hints to Remember the Unit Circle There will be another quiz next class!

Unit Circle Trig Review: SOH CAH TOA

For any right triangle the trig ratios will work What happens when we get angles greater than

90, negative angles etc? We can use the Unit Circle to redefine the trig ratios.

Definition of Trig Ratios in Unit Circle Draw the Unit Circle on the coordinate plane. Drop an altitude and create a right triangle

with angle theta. Define each of the trig ratios based on this

generic triangle.

Definitions of Trig Functions in the Unit Circle Theta is an angle measure in radians. (x,y) is a point on the unit circle.

Examples: Find each of the requested trig ratios on the

unit circle: Step 1: Find a co-terminal angle between 0

and Step 2: Use the trig functions to evaluate the

sin or cos

Name the 4 presidents assassinated while in office. Lincoln Kennedy McKinley Garfield

CFU

Paper Plate Unit Circle Use colored pencils and a straight edge to

make a unit circle on a paper plate.