Normal subgroups and homomorphisms Flashcards
1
Q
normal subgroup if
A
N^g = N
2
Q
If G is abelian, all subgroups of G are
A
If G is abelian, all subgroups of G are normal subgroups
3
Q
If G is a group, N≤ G, N≤Z(G) then N is
A
If G is a group, N≤ G, N≤Z(G) then N is a normal subgroup of G
4
Q
If G a group N≤G, [G:N] = 2, then…
A
If G a group N≤G, [G:N] = 2, then N is a normal subgroup of G
5
Q
G/N =
A
G/N = {Ng | g in G} = {gbar| g in G}
6
Q
If G/ Z(G) is cyclic, then
A
If G/ Z(G) is cyclic, then G is abelian
7
Q
H is a normal subgroup of G <=>
A
H/N is a normal subgroup of G/N
8
Q
homomorphism
A
(g1g2)θ = (g1θ)(g2θ)
9
Q
|G/N| =
A
[G:N] = |G|/|N|
10
Q
First isomorphism theorem
A
G/ker(theta) is isomorphic to Gtheta