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September 11th, 2017, 03:30 PM   #1
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Unhappy Need help with partial function problem.

It's a problem from discrete math, not calculus. I don't know where else to post it though.

Can someone please help me understand what exactly this question is asking me to do?

"Show that a partial function from A to B can be viewed as a function f* from A to B U {u}, where u is not an element of B and f*(a) = {f(a) if a belongs to the domain of definition of f, OR u if f is undefined at a}"

I can see that it makes sense, but I don't know how to show that, or how to solve this problem. Please help.

Last edited by skipjack; September 11th, 2017 at 04:40 PM.
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September 11th, 2017, 05:01 PM   #2
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It doesn't make sense to me - mainly because it's vague. What does "viewed as" mean? It would seem that the partial function is named f, but the problem doesn't explicitly say so - it just refers to f without explaining what f is.

For it to make a little sense, A and B need to be sets, but the problem doesn't explicitly state that they are. If they are, a partial function from A to B is simply a function from C to B, where C is a subset of A. This definition doesn't require that C is known.

Without a definition of "viewed as", it's impossible to make any further progress with this problem.
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September 11th, 2017, 05:16 PM   #3
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Quote:
Originally Posted by skipjack View Post
It doesn't make sense to me - mainly because it's vague. What does "viewed as" mean? It would seem that the partial function is named f, but the problem doesn't explicitly say so - it just refers to f without explaining what f is.

For it to make a little sense, A and B need to be sets, but the problem doesn't explicitly state that they are. If they are, a partial function from A to B is simply a function from C to B, where C is a subset of A. This definition doesn't require that C is known.

Without a definition of "viewed as", it's impossible to make any further progress with this problem.
A and B are sets. It doesn't say how "viewed as" is defined
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September 11th, 2017, 05:24 PM   #4
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https://en.wikipedia.org/wiki/Analytic_continuation

Above may be what you need.
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