Determine whether the following subsets are subspaces of the given vector space. Either prove that the set is a subspace or give a counterexample to prove that it is not. (a) The subset TC P3 pf polynomials of degree less than or equal to 3 that are of the form p(x) = 1 + ₁x + c₂x² + c32³, where C₁, C2, C3 are scalars in R. (b) The set s={[%a S { a b] : = a,b ERC M2,2, that is, the subset of all 2 x 2 matrices of A where a11 = a22 and a21a12.