Aside: The Dual Matrix
- If v=[x,y,z] is a vector, the matrix
- Cross-product as a matrix multiply: v*a = v x a
- helps define rotation about an arbitrary axis
- angular velocity and rotation matrix time derivatives
- Geometric interpretation of v*a
- project a onto the plane normal to v
- rotate a by 90° about v
- resulting vector is perpendicular to v and a