1. Point mirroring in 3-D space leads to a change of orientation of the volume 3-blades. We know this spatial inversion better from re?ection in a mirror. Show that this has indeed the same effect. (Hint: Let the mirror plane be characterized by a 2-blade B, and let a be a vector perpendicular to B (for example, a = B∗). Then de?ne the linear transformation performing the mirror re?ection, and apply it to a sensibly chosen 3-blade in this setup. Why does your result generalize to arbitrary 3-blades?)