## Unit 5 - __Lesson 2 - Domain of trigonometric functions using the unit circle__

__Lesson Standards__- Understand radian measure of an angle as the length of the arc on the unit circle subtended by the angle.
- Explain how the unit circle in the coordinate plane enables the extension of trigonometric functions to all real numbers, interpreted as radian measures of angles traversed counterclockwise around the unit circle.

__Essential Questions__- How can you relate circumference to the radian units of the
unit circle?
- If you calculate the circumference of the unit circle what answer do you get?
- Therefore, what is one fourth of the circumference and where can this be found on the unit circle?
- The circumference of a circle is used to find __________ because the shape of the circle is round and not straight.

**Students:**You student should be accessing the online videos to help drive instruction as well as to reinforce your teaching notes. The guided notes help to keep the students on task and to make sure they are prepared for the practice problems and activity. Your students should be showing you that they understand this material through ticket-out-the-door problems, turning in the worksheets for the teacher to review, or having students work problems on the board to show their understanding of this AKS.

**Lesson Videos**
Unit Circle with Degrees |
Unit Circle with Radians |
Cool Unit Circle Song & Video |