------------------------------------
students in general had difficulty with the concept of
L-invariant and cyclic subspace, since they seem to have difficulties in
presenting #4a and apply it to 4b. Many students as well forget to give the
basis of nullspace in Problem set 5 #1.
------------------------------------
Problem Set 4
-  Question 1:  Some students were just not starting the question
correctly.  They were declaring the variable to be elements of the wrong
set.
-  Question 3:  Again some problems with declaring variables.  Letting v1,
v2 be elements of V rather than Em.  T(v1) = mv1 only if v1 is in Em.
        Also quite a few students forgot to consider the presence of the
zero vector.

------------------------------------