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antiemptyv
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Homework Statement
Let H be a normal subgroup of prime order p in a finite group G. Suppose that p is the smallest prime dividing |G|. Prove that H is in the center Z(G).
Homework Equations
the Class Equation?
Sylow theorems are in the next section, so presumably this is to be done without them.
The Attempt at a Solution
Not completely sure of a solution, but here's (at least some of) what we know:
1. Since H is normal, [tex]ghg^{-1} \in H[/tex].
2. Since [tex]|H|[/tex] is prime, [tex]H[/tex] is cyclic and abelian.
3. [tex]G[/tex] is finite, with order [tex]|G| = p^nq[/tex].
4. The normalizer [tex]N(H)[/tex] (stabilizer under conjugation) is all of [tex]G[/tex]...
5. ...so [tex]|G| = |N(H)|[/tex] ??
6. Probably some more relevant properties.
And we want to show that [tex]H \subseteq Z(G)[/tex], i.e. [tex]H \subseteq \{g \in G | gx = xg \forall x \in G\}[/tex]
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