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

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Angela Richardson

Posts: 42
From: UK
Registered: 6/22/11
Re: Functions w/ Injective and Surjective
Posted: Oct 13, 2012 2:45 AM
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att1.html (2.1 K)

surjective: f(n) does not have two values for the same n

injective: f(n) does not have two different n giving the same value
bijective: both injective and surjective

a) inverse of answer to b)

b) f(n)=number of divisors of n

c) f(n)= n-1 if n is even, n+1 if n is odd



________________________________
From: Edward <discussions@mathforum.org>
To: discretemath@mathforum.org
Sent: Friday, 12 October 2012, 5:30
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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