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Topic: Functions w/ Injective and Surjective
Replies: 6   Last Post: Oct 14, 2012 12:20 PM

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Ben Brink

Posts: 197
From: Rosenberg, TX
Registered: 11/11/06
RE: Functions w/ Injective and Surjective
Posted: Oct 13, 2012 10:09 PM
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Edward,
For (c), easiest choice is the identity function. For (a), one of the easiest choices is the doubling function, f(x) = 2x. For (b), I can't think of a surjective function that's not injective. Someone on this site should have further comments on that. Thanks,
Ben


> Date: Fri, 12 Oct 2012 00:30:11 -0400
> From: discussions@mathforum.org
> To: discretemath@mathforum.org
> Subject: Functions w/ Injective and Surjective
>
> How could I give an example that function f: ??? that is
> (a.) injective but not surjective
> (b.) surjective
> (c.) and both bijective
>
> Using N obviously it involves Natural numbers. How can this be shown?





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