ABSTRACT
Let A1⊕A2 and A1⊕A3 be two rooted gyrovectors with a common tail A1, shown in Fig. 7.1. They include the gyroangle α1 = ∠A2A1A3 = ∠A3A1A2, the radian measure of which is given by the equation
shown in Fig. 7.1. Accordingly,
, (7.2)
of trigonometry. In the context of gyroangles, as in (7.1)–(7.2), we refer these functions of trigonometry to as the functions gyrocosine and gyroarccosine of gyrotrigonometry.