Double Angle Identities Calculator
The Double Angle Identities Calculator computes sin 2θ, cos 2θ, and tan 2θ from an angle using the double-angle formulas. Enter the angle in degrees.
Formula
sin 2θ = 2 sin θ cos θ; cos 2θ = cos²θ − sin²θ; tan 2θ = 2 tan θ / (1 − tan²θ)
- Double-angle identities express functions of 2θ in terms of θ.
- cos 2θ also equals 1 − 2sin²θ or 2cos²θ − 1.
θ = 30°
Inputs
- Angle θ: 30 °
sin 60° = 0.866, cos 60° = 0.5, tan 60° ≈ 1.732.
Frequently asked questions
What is the double angle formula for cosine?
cos 2θ = cos²θ − sin²θ, which also equals 1 − 2sin²θ and 2cos²θ − 1.