Kahn+Academy+Placemark

http://www.khanacademy.org/video/linear-algebra--eigenvalues-of-a-3x3-matrix?playlist=Linear+Algebra http://www.khanacademy.org/video/linear-algebra---finding-eigenvectors-and-eigenspaces-example?playlist=Linear+Algebra http://www.khanacademy.org/video/linear-algebra--example-solving-for-the-eigenvalues-of-a-2x2-matrix?playlist=Linear+Algebra