 Tangent half-angle formula

The tangent half-angle formulas relate the tangent of half of an angle to the sine and cosine of the angle itself. The tangent half-angle formulas are given by: 1. In terms of sine and cosine: \[ \tan\left(\frac{\theta}{2}\right) = \frac{\sin(\theta)}{1 + \cos(\theta)} \] 2.