Outline
Trigonometric Identities
Table of Contents
Pythagorean Identities
Even/Odd Identities
Cofunction Identities
Identities from Similar Right Triangles
Sum & Difference Identities
- Sine & Cosine of a Sum: Discovery
- Trig ID: Geometric Investigation
- Tangent of a Sum: Discovery
- Tangent of a Difference: Trig Identity Puzzle + Proof!
- Cotangent of a Sum: Discovery
- Trig ID (2) - Geometric Investigation
- Trig Identity (3) - Geometric Investigation
- Double Angle Trig Identity: Proof via Equal Areas
- Trig Identity Shown Graphically
Other Identities
Laws of Sines and Cosines
Older (Earlier) Applets