JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY, cilt.44, sa.6, ss.1313-1327, 2007 (SCI-Expanded)
We review the algebraic structure of H' and show that H' has a scalar product that allows as to identify it with semi Euclidean E-2(4) We show that a pair q and p of unit split quaternions in H' determines a rotation R-qp : H' <-> H'. Moreover, we prove that R-qp is a product of rotations in a pair of orthogonal planes in E-2(4). To do that we call upon one tool from the theory of second ordinary differential equations.