Math. 311                                         Spring 2000

                     HOMEWORK SUMMARY REPORT


  Assignment number: 4          
    
  Problem number:  3.4.7

  Number of papers received: 1  

  Reviewing committee (Greek letter): Pi       

  List all participating members:  Mathew Hobson, Gabriel Valderrama



  Author[s] of paper[s] chosen for publication:                  

  Anish Joseph (after revision)


  Comments:
        Anish's solution is well thought out, step by step, until the last
line where he writes down the answer.  Somehow, through incorrect matrix
multiplication, he obtained the incorrect answer, though everything before
it looks good.  Very little verbal explanation is done, so that somebody
who does not already know how to take a partial will probably not be able
to make out what exactly he did in the first line of computing the partial
of B.  A simple matrix display of what the generic definition of a partial
would do.


INSTRUCTOR'S COMMENT:  Remember that "the directional derivative ... in
THE DIRECTION OF [something]" calls for first finding a UNIT VECTOR in
that direction.  (See the report on Ex. 3.4.9, next exercise.)