Trigonometry
Advanced

Double Angle: Tangent

Tangent of twice an angle.

Formula

tan⁡2θ=2tan⁡θ1−tan⁡2θ\tan 2\theta = \frac{2\tan\theta}{1 - \tan^2\theta}

Variables

\thetaAngle

Did You Know?

The tangent double-angle formula appears in optics when light reflects and the angle effectively doubles.

double angleidentity