📈ap pre-calculus review

Double-angle identities

Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2027 exam
Verified for the 2027 examWritten by the Fiveable Content Team • Last updated August 2025

Definition

Trigonometric identities that express the sine or cosine of twice an angle in terms of trigonometric functions of the original angle, derived from sum identities.

AP course connection

Topic 3.12: 3.12 Equivalent Representations of Trigonometric Functions

Unit 3

"Double-angle identities" also found in: