Alphabeta Math

Group Homomorphisms and the Isomorphism Theorems: Examples and Counterexamples

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✓ 5 results · all verified · 0 also independently AI-judged
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1 · Prerequisites
2 · Logical flowchart

3 · Items

Example

For n≥2, reduction ℤ→ℤ/n has kernel nℤ and realises ℤ/n by the first isomorphism theorem

Counterexample

The doubling endomorphism of (ℤ,+) has trivial kernel but is not surjective

Example

The trivial homomorphism G→ H has kernel G and image {e_H}

Example

Every inner automorphism of an abelian group is the identity

Example

Conjugation by (1 2) in Sym({1,2,3}) exchanges the transpositions (1 3) and (2 3)

Sources