Feedback: Test #1
MA2321, Fall '03, T. Olson

General Info. (applies to all tests)

Each time you get a test back, you should go through it thoroughly (preferably with one or two other students). Make sure you understand what each problem was asking and how to answer each problem correctly, completely, and clearly. If you cannot figure something out, check your notes or textbook. If you're still not sure, go through the test with me or a coach from the Math. Learning Center.

• Marks:
  ``$\surd$'' $\Longrightarrow$ Correct
  ``X'' $\Longrightarrow$ Wrong
  
  ``O.K.'' $\Longrightarrow$ ``Okay, BUT ...'' (I probably gave you full credit, but something is wrong: perhaps your answer was based on an incorrect previous answer or you missed the point of the question or I couldn't tell how you arrived at your answer)
  
  ``+2'' $\Longrightarrow$ partial credit (in a circle)
  

• Numbers/score:
  • At the bottom outer corner of each page is the total number of points you earned on that page.
  • On the top of your first page is your total for the test. Check that your individual page totals add to this number.

Test #1 Comments
You could earn a maximum of 5 points on each question (or part).

What I was really asking, in certain questions:

14.

What equations do you solve to find the nullspace of F? How do you write the solution set? (It is more than just one vector.)

15.

How is the general solution related to the homogeneous solution (from problem 14) and a particular solution? (I did NOT want you to punch the augmented matrix in your calculator and use ``rref'')

16a.

Did you know that matrix multiplication is not commutative? (i.e., order of multiplication matters, so $AB \not= BA$)

16b.

You can't divide both sides of an equation by a matrix ('cause there's no such thing as matrix division), so how do you ``undo'' matrix multiplication?

19.

Do you know what ``linear combination'' means?