Source: /cirosantilli/eigendecomposition-of-a-real-symmetric-matrix

= Eigendecomposition of a real symmetric matrix

= The eigendecomposition of a real symmetric matrix is done with orthogonal matrices
{synonym}

The general result from <eigendecomposition of a matrix>:
$$
M = QDQ^{-1}
$$
becomes:
$$
M = ODO^T
$$
where $O$ is an <orthogonal matrix>, and therefore has $O^{-1} = O^T$.