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-   -   Onto and One-To-One Function (http://mymathforum.com/number-theory/22106-onto-one-one-function.html)

whatlifeforme October 29th, 2011 10:23 AM

Onto and One-To-One Function
 
Why is the following function (f(n) = n + 17), one-to-one, but not onto?

The function should be able to take on values of (-inf,inf) in the codomain or range, correct?

CRGreathouse October 29th, 2011 12:45 PM

Re: Onto and One-To-One Function
 
I don't know. What's the domain? You'll get different answers depending on whether it's N -> N or R -> R or something else.

whatlifeforme October 29th, 2011 03:35 PM

Re: Onto and One-To-One Function
 
N -> N

CRGreathouse October 29th, 2011 03:51 PM

Re: Onto and One-To-One Function
 
What value of n gives f(n) = 3?

whatlifeforme October 29th, 2011 04:22 PM

Re: Onto and One-To-One Function
 
for the given fcn. (-14)... is that what you are asking?

f(n) = n + 17;
(-14) + 17 -> "3"

CRGreathouse October 29th, 2011 04:25 PM

Re: Onto and One-To-One Function
 
But -14 isn't in N.


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