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Topic: Onto Functions
Replies: 2   Last Post: Dec 27, 2012 11:56 PM

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Posts: 127
Registered: 12/3/04
Re: Onto Functions
Posted: Dec 1, 2012 10:45 AM
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att1.html (1.1 K)

I think some of the issue stems from the incompleteness of the
description. We don't say functions are into or onto without describing the set as
well. y = x^2 is onto the non-negative real numbers, but y = x^2 is not onto
the set of real numbers.

Most of the time we take the set for granted because we think we're
implying the set of real numbers, but for the sake of completeness the set must
be included in our wording and explanation.

Steve Goldman
Half Hollow Hills HS East
Dix Hills, NY

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