Here we discuss the examples of subspaces as well as the intersection and union of subspaces. Sorry for the audio problems in between.
0:00 : Intro Vector spaces
1:31 : Intro Subspaces
3:22 : Line not passing through origin
5:40 : Examples of Subspaces
9:52 : Rank 1 matrices
12:18 : Union of 2 subspaces
15:04 : Intersection of 2 subspaces
18:04 : Proof Intersection of 2 subspaces is subspace