Ray

Definition

A ray is a part of a line that starts at a point and extends infinitely in one direction. It is used to represent angles and directions in trigonometric functions.

5 Must Know Facts For Your Next Test

1. A ray originates from a single point called the endpoint.
2. The notation for a ray starting at point A and passing through point B is written as $\overrightarrow{AB}$.
3. Rays are used to form angles; the common endpoint of two rays is called the vertex.
4. In trigonometry, rays can represent angle measures on the unit circle.
5. Understanding how to identify and work with rays is crucial for solving problems involving sine and cosine functions.

Review Questions

• What is the notation for a ray that starts at point A and passes through point B?
• How do rays relate to the formation of angles?
• Why are rays important when studying sine and cosine functions?

Related terms

Angle: An angle is formed by two rays with a common endpoint called the vertex.

Vertex: The common endpoint where two rays meet to form an angle.

Unit Circle: $$A circle with radius one centered at the origin (0,0) in the coordinate plane.$$