Subspaces Suppose X is a set with a binary operationo so given any pair 1. x2∈X we have1ox2∈X. Let Y be a subset of X.We say Y is closed under o if for any pair y1,y2∈Y we have1o2∈Y. Definition Let(V,+,.)be a vector space and U C V be a subset.Then U is said to be a subvector space or subspace of V if (i)U is closed under + (ii)U is closed under.. 4口++心++左+4生+定QCSubspaces Suppose X is a set with a binary operation ◦ so given any pair x1, x2 ∈ X we have x1◦x2 ∈ X. Let Y be a subset of X. We say Y is closed under ◦ if for any pair y1, y2 ∈ Y we have y1◦y2 ∈ Y . Definition Let (V, +, •) be a vector space and U ⊂ V be a subset. Then U is said to be a subvector space or subspace of V if (i) U is closed under +, (ii) U is closed under •