Subspaces 3. determine whether each of the subsets of the given vector space are a. is the set of polynomials ao + a1x + a2x2 +a3x*, for which ao = 0, a subspace of the set of all polynomials with degree less than or equal to three? b. is the set of polynomials ao + aix + a2x2 subspace of the set of all polynomials with degree less than or equal to three? azx3, for which ao + aj + a2 + a3 = 0, a + c. is the set of all functions f, such that f(x)