eigenvalues
Eigenvalues and eigenvectors of a square matrix: definition via \(A\mathbf{v} = \lambda\mathbf{v}\), characteristic equation \(\det(A – \lambda I) = 0\), eigenspaces, and diagonalization.
A matrix is diagonalizable if there exists a basis of eigenvectors and it can be written in the form \( A = P D P^{-1} \) with \( D \) diagonal.