
Description This lecture focuses on orthogonal matrices and subspaces. Professor Strang reviews the four fundamental subspaces: column space C(A), row space C(AT), nullspace N(A), left nullspace N(AT). Summary Examples: Rotations Reflections Hadamard matrices Haar wavelets Discrete Fourier Transform (DFT) Complex inner product Related section in textbook: I.5 Instructor: Prof. Gilbert Strang