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#1 2007-10-30 08:38:47

xXxEmZyxXx
Member
Registered: 2007-10-15
Posts: 12

surjective function

let A B be sets
f:A->B
suppose there is a function h:B->A with the property that f(h(b)=b for all bEB
show that f has to be surjective

please help will be much appreciated!!!dunnodunno

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#2 2007-10-30 09:03:15

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Re: surjective function

For all bB, c = h(b) ∈ A and f(c) = b. That is all. QED

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#3 2007-10-30 10:17:37

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: surjective function


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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