(a) Explain why these vectors cannot possibly be independent. (b) Form a matrix A whose columns are the u_i's and compute the rref(A). (c) Solve the homogeneous system Ax = 0 in parametric form and then in vector form. (Be sure the clearly identify the row operation used). (d) Use the vector form solution to write down two relations involving the vectors u_i, then solve for the vectors corresponding to the free variables. (e) Explain why the u_i vectors corresponding to the pivot variables form a basis for the subspace U := Span{u_1, ..., u_5} (f) Use the technique in Example 4.94 of the Kuttler textbook to extend the basis found in (e) to a basis for R^4. (Note: you can use the same row operations as in part (c))