Assignment 1, MATH 240: Spring 2008.
  Due 10am, Monday Jan 21st.
  Please post your solutions in the RIGHT mailbox outside the lab AQ 4135.
  Sorry, no late assignments will be accepted.
  
  Study the material in sections 1.1, 1.2, and 1.3.

  From the text Fraleigh & Beauregard (3rd edition)

     1.1 exercises 2, 10, 23, 26, 35, 38, 39, 40(a), 42(a).
     1.2 exercises 2, 8, 9, 12, 16, 25, 33, 36, 40, 44.
     1.3 exercises 4, 5, 15, 16, 18, 21, 26, 32, 39, 43.
     1.4 exercises 1, 2, 16, 18.
  
  Note, I've assigned 12 odd numbered exercises.  The answers to these
  are in the back of the book.  You don't have to hand those in.
  However, you will be examined on them.
  
  Additional problems.

  1: Study and write out the proof of the triangle inequality (Theorem 1.5).
     For each step of the proof indicate which properties are being used.
  
  2: Suppose A and B are two anti-diagonal matrices, i.e., matrices of the form
  
      [0  0  a]
      [0  b  0]
      [c  0  0]

     where a, b, c are real numbers.  Prove or disprove  A B = B A .