## Linear Algebra Done Right 2nd Edition - Chapter 1 Exercise 9

**Chapter 1 Exercise 9.**

Prove that the union of two subspaces of *V* is a subspace of *V* if and only if one of the subspaces is contained in the other.

Therefore, by 1 and 2, the union of two subspaces of *V* is a subspace of *V* if and only...Read More »