grandes-ecoles 2015 Q3a

grandes-ecoles · France · x-ens-maths__pc Proof Proof of Set Membership, Containment, or Structural Property
Let $\mathcal{U}$ and $\mathcal{V}$ be two vector subspaces of $\mathbb{R}^{n}$ such that $$\operatorname{dim} \mathcal{U} + \operatorname{dim} \mathcal{V} > n.$$ Show that $\mathcal{U} \cap \mathcal{V}$ is not reduced to $\{0\}$.
Let $\mathcal{U}$ and $\mathcal{V}$ be two vector subspaces of $\mathbb{R}^{n}$ such that
$$\operatorname{dim} \mathcal{U} + \operatorname{dim} \mathcal{V} > n.$$
Show that $\mathcal{U} \cap \mathcal{V}$ is not reduced to $\{0\}$.