Announcement

• HW5, due Fri 11/17 @ 11:59pm.

Q&A

• Why is the volume of a parallelepiped the determinant of the matrix whose columns are the vectors defining the parallelepiped? Let $\mathbf{A} = \mathbf{Q} \mathbf{R}$ be the QR factorization. Then the volume of the parallelepiped defined by the columns of $\mathbf{A}$ is the product of diagonal entries of $\mathbf{R}$.

Today

• Matrix determinant.

• Eigenvalues and eigenvectors.