Definition
Negative angles represent clockwise rotation from the initial side.
Why It Matters
Angles are not just magnitudes; they have direction. Ignoring negative angles (clockwise rotation) leads to fundamental errors in navigation, robotics, and physics where the ‘sense’ of rotation is as important as the amount of rotation.
Core Concepts
- They can be converted to positive coterminal angles by adding full rotations. Odd/even trig symmetry often simplifies negative-angle expressions.
- This concept is part of the chapter-by-chapter synthesis from Trigonometry For Dummies.
- It should be merged with existing math notes if a stronger canonical note already exists.