Trigonometric identities are essential equations in trigonometry that express relationships between trigonometric functions. These identities help simplify expressions, solve equations, and prove other mathematical results. The fundamental trigonometric identities include:
1. Reciprocal Identities
These identities express trigonometric functions in terms of their reciprocals:
2. Pythagorean Identities
These identities are derived from the Pythagorean Theorem:
3. Quotient Identities
These identities express tangent and cotangent in terms of sine and cosine:
4. Cofunction Identities
These identities relate trigonometric functions of complementary angles:
5. Even-Odd Identities
These identities describe the symmetry properties of trigonometric functions: