For V a vector space, and W_1, W_2 subspaces of V, prove....

[mooshupork34]

This problem was puzzling me, and since I have a test on it sometime next week, I would really appreciate it if someone could explain how it is done. Thanks in advance.

Let V be a vector space, and let W_1 and W_2 be subspaces of V. Prove that W_1 (insert upside down U symbol here) W_2 is a subspace of V. [Remember to show that W_1 (insert upside down U symbol here) W_2 is nonempty.]

 

[Unco]

What are the requirements for a subset of a vector space to be a subspace, Moosh? Let's see your effort at showing how they're satisfied.