# Math Help - Epimorphism

1. ## Epimorphism

Let R be a ring with unity, 1. Let S be a ring and suppose phi: R --> S is an epimorphism. Prove that phi(1) is a unity for S.

2. Originally Posted by Coda202
Let R be a ring with unity, 1. Let S be a ring and suppose phi: R --> S is an epimorphism. Prove that phi(1) is a unity for S.

Let s be in S ==> there exists r in R s.t. F(r) = s (F instead phi) ==>
s*f(1) = f(r)*f(1) = f(r*1) = f(r) = s/

Tonio