are linearly independent if and only if there exists no real
numbers 
such that
(2b) Equation (3) in the assignment will give you four linear equations for
the four components of 
, which you should be able to solve
very easily.
(2c) Having got the components of , it is easy to find the
value of 
.
(2d) This problem is similar to part (2a).
and 
. Then evaluate 
and
. You should get
different results.
(4b) Compare how 
and 
transform.
(4c) No hint here!!