Computation of Bases of Various Vector Spaces
For each of the following vector spaces, give its dimension and a basis.
(a) the set of all symmetric 4 x 4 matrices,
(b) the subspace of P3 consisting of those polynomials in P3 whose graphs
pass through the origin
(c) the set of all vectors in R3 that are orthogonal to v = (1,2,-1)