9.2. EXERCISES 169
27. Determine whether the following vectors are a basis for R3. If they are, explain whythey are and if they are not, give a reason and tell whether they span R3.(
1 0 3)T
,(
0 1 0)T
,(
1 2 0)T
,(
0 0 0)T
28. Determine whether the following vectors are a basis for R3. If they are, explain whythey are and if they are not, give a reason and tell whether they span R3.(
1 0 3)T
,(
0 1 0)T
,(
1 1 3)T
,(
0 0 0)T
29. Consider the vectors of the form 2t +3s
s− tt + s
: s, t ∈ R
.
Is this set of vectors a subspace of R3? If so, explain why, give a basis for the sub-space and find its dimension.
30. Consider the vectors of the form
2t +3s+us− tt + s
u
: s, t,u ∈ R
.
Is this set of vectors a subspace of R4? If so, explain why, give a basis for the sub-space and find its dimension.
31. Consider the vectors of the form
2t +ut +3u
t + s+ vu
: s, t,u,v ∈ R
.
Is this set of vectors a subspace of R4? If so, explain why, give a basis for the sub-space and find its dimension.
32. If you have 5 vectors in F5 and the vectors are linearly independent, can it always beconcluded they span F5? Explain.
33. If you have 6 vectors in F5, is it possible they are linearly independent? Explain.
34. Suppose A is an m× n matrix and {w1, · · · ,wk} is a linearly independent set ofvectors in A(Fn) ⊆ Fm. Now suppose A(zi) =wi. Show {z1, · · · ,zk} is also inde-pendent.