Eigenvectors of projection and reflection matrices
Let \( P \) and \( R \) be the projection and reflection matrices for a
vector \( a \). \( P \) has eigenvalues \(1\) and \(0\), while \( R \) has eigenvalues \(1\) and \(-1\). We can also say [what about the eigenvectors
\( P \) and \( R \)?].