Lesson 1

1. Lesson 1

1.5. Explore

Mathematics 20-1 Module 2

Module 2: Trigonometry

Explore

Try This 1 is based on an extended definition of cosine and sine that allows for any angle 0° ≤ θ ≤ 360°. ∠θ in Try This 1 is an example of an angle in standard position. Before going further, it is important to discuss angles in standard position.

Angles in standard position

have their vertex at the origin (point (0, 0) on the Cartesian plane)

are formed by an initial arm on the positive x-axis and a terminal arm

are “swept out” in a counterclockwise direction from the initial arm to the terminal arm

This is a picture of an angle in standard position. The initial arm is the positive x-axis, the vertex is at the origin, and the terminal arm is in quadrant 2. The angle is marked as theta equals 122 degrees.

Save Module 2 Glossary Terms in your course folder now.

Here are some of the words you will want to define in Module 2 Glossary Terms in this lesson:

standard position
vertex
initial arm
terminal arm
unit circle