Trigonometric Functions on the Unit Circle
This page delves into the definitions of cosine and sine using the unit circle, as well as introducing the concept of radians.
Key points:
- Cosine x−coordinate and sine y−coordinate are defined using points on the unit circle.
- One radian is the angle subtended by an arc length equal to the radius.
- The relationship between degrees and radians is given: π radians = 180°.
Definition: Circonferenza goniometrica seno e coseno refers to the representation of sine and cosine on the unit circle.
Formula: sin²θ + cos²θ = 1 Pythagoreanidentity
The page also provides key values for sine and cosine at notable angles 0°,90°,180°,270°,360°.
Example: cos 0° = 1, sin 0° = 0; cos 90° = 0, sin 90° = 1