1. The problem statement, all variables and given/known data Let W1 and W2 be two subspaces of R^n. Prove that their intersection is also a subspace. 2. Relevant equations 3. The attempt at a solution I know that in R^2 and R^3 the intersection would be the origin, which would be the zero vector, which would be a subspace, but I don't know how to make a general argument about this.