Solution
= Solution
Take
$$
\boxed{B=\begin{pmatrix}0&-1\\1&0\end{pmatrix}.}
$$
Its <characteristic polynomial> is $\lambda^2+1$, whose roots are $i$ and $-i$. Thus this real <matrix> has no real <eigenvalues>.
= Solution
Take
$$
\boxed{B=\begin{pmatrix}0&-1\\1&0\end{pmatrix}.}
$$
Its <characteristic polynomial> is $\lambda^2+1$, whose roots are $i$ and $-i$. Thus this real <matrix> has no real <eigenvalues>.