00:01
So for cn, n is greater or equal to 3, by removing any vertex and its incident edges, it will become line, looks like this one.
00:23
So still connected, so no cut vertices.
00:37
For b, for wn, n is greater equal to 3, if we remove, the vertex in the center, then wn will become cn, which is still connected.
01:09
If we remove the vertex not in the center, then every vertex has an edge with central vertex, which means it is still connected.
01:47
So no cut vertices for c.
02:01
Kmn, m is greater equal to 2, n is greater equal to 2, remove any vertex and its incidence, it becomes k m minus 1 in or k m m minus 1, both of them are connected.
02:31
This means it has no cart vertices.
02:41
The last one for qn is greater equal to 2.
02:50
By symmetry, we can assume the vertex we removed is 1 -0 -0...