- #1

Physicsissuef

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## Homework Statement

Prove that one copying [tex]f:A \rightarrow B[/tex] is injection, only if [tex]x_1,x_2 \in A[/tex] and [tex]x_1 \neq x_2 \Rightarrow f(x_1) \neq f(x_2)[/tex]

## Homework Equations

## The Attempt at a Solution

I have not idea at all. Can somebody, please help?