Discussion:
Q(a) Draw a graph with numbered and directed edges (and numbered vertices) whose incidence matrix is
A =[ -1 1 0 0
-1 0 1 0
0 1 0 -1
0 0 -1 1]
(b) Is this graph a tree?
(c) Show that removing the last edge produces a spanning tree.
(d) The remaining rows are a basis for ____?