  Let $A=[a_{ij}]\in O_3(\mathbb{R})$. We give several different proofs of the
fact that the vector $$ V:=\left[\begin{array}{ccc} \displaystyle
\frac{1}{a_{23}+a_{32}} & \displaystyle \frac{1}{a_{13}+a_{31}} & \displaystyle
\frac{1}{a_{12}+a_{21}} \end{array}\right]^T, $$ if it exists, is an
eigenvector of $A$ corresponding to the eigenvalue $1$.
