My students only: If you submitted the early homework by 5:00 Wednesday, you don't need to turn in problems 12 or 31 from section 4.1, problem 3 from section 4.2, or problems 9 or 20 from section 4.3 on Friday. However, please make a note that you have done so.
Question 1: Let A be an m by n matrix. Prove that the columnspace of A is a subspace of Rm.
Question 2:
Let H=
15-3124
417103
-15-783
-24-841
-22-603
, and J=
10220
01-120
00001
00000
00000
.
H is row-equivalent to J. Find a basis for the nullspace of H.
Question 3: Find a basis for the columnspace of H.