Posted by haifeng on 2012-07-19 16:43:00 last update 2012-07-19 16:43:00 | Answers (1) | 收藏
\[ g=\begin{pmatrix} a^2-b^2-c^2+d^2 & -2(ab+cd) & -2(ac-bd)\\ 2(ab-cd) & a^2-b^2+c^2-d^2 & -2(ad+bc)\\ 2(ac+bd) & 2(ad-bc) & a^2+b^2-c^2-d^2 \end{pmatrix}. \]
