Solution
= Solution
The <Levi-Civita symbol> vanishes when two indices coincide, so
$$
\boxed{\operatorname{tr}M=\delta_{ii}+2\epsilon_{iik}a_k=3.}
$$
= Solution
The <Levi-Civita symbol> vanishes when two indices coincide, so
$$
\boxed{\operatorname{tr}M=\delta_{ii}+2\epsilon_{iik}a_k=3.}
$$