Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Trigonometric identities are equations that relate different trigonometric functions. They allow us to simplify and manipulate trigonometric expressions.
Related terms
Pythagorean Identity: This identity relates the three basic trigonometric functions (sine, cosine, and tangent) with the Pythagorean theorem.
Double Angle Identity: This identity allows us to express a trigonometric function of twice an angle in terms of the original angle.
Reciprocal Identity: This identity expresses a trigonometric function in terms of its reciprocal (e.g., cosecant is the reciprocal of sine).