sinα=2tanα21+tan2α2 sin\alpha = \frac{2tan\frac{\alpha}{2}}{1+tan^2\frac{\alpha}{2}}

    cosα=1−tan2α21+tan2α2 cos\alpha = \frac{1-tan^2{\frac{\alpha}{2}}}{1+tan^2{\frac{\alpha}{2}}}

    tanα=2tanα21−tan2α2 tan\alpha = \frac{2tan{\frac{\alpha}{2}}}{1 - tan^2{\frac{\alpha}{2}}}