Let Determine if p is in Col A, where A = [v1 v2 v3]. Determine if is in Nul A. (Hint: A vector x is in Nul A if Ax = 0. This is much easier than finding the entire null space which is the solution set of Ax = 0. Moral: Checking whether something is a solution is one story and finding all solutions is another.) Let Find bases for Col A and Nul .4. and then state the dimension of subspaces. An echelon form of A is given below for your convenience.