Haversine

The haversine function $\mathrm{haversin} \colon \mathbb{C} \rightarrow \mathbb{C}$ is defined by $$\mathrm{haversin}(z)=\dfrac{\mathrm{versin}(z)}{2},$$ where $\mathrm{versin}$ denotes the versine.

References

• 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.3.147$