In: Advanced Math
3. In R4 , does the set {(1, 1, 1, 0,(1, 0, 0, 0),(0, 1, 0, 0),(0, 0, 1, 1)}, span R4? In other words, can you write down any vector (a, b, c, d) ∈ R4 as a linear combination of vectors in the given set ? Is the above set of vectors linearly independent ?
4. In the vector space P2 of polynomials of degree ≤ 2, find explicitly a polynomial p(x) which is not in the span of the set {x + 2, x2 − 1}.
5. Let S be the subspace of P2 defined by S := {ax2 + bx + 2a + 3b : a, b ∈ R}, for different choices of real numbers a and b (you don’t need to show here that S is indeed a subspace, and can assume. But is a good practice problem). Find a basis, and hence dimension for S.