Function Example Ideas: Tips, Suggestions, and Help

[iscreamath]

http://answerboard.cramster.com/other-topic-5-311900-0.aspx"

I need help getting some ideas for an example of a function.
Any help, ideas, suggestions, and/or tips are greatly appreciated.
Thanks for looking at this question!

 

[Dick]

You are sort of muddling up domain and range. If f:A->B then H must be a subset of the range B, right? And if b is an element of B such that there is no a such that f(a)=b you are defining f^(-1)({b})={} (the empty set). Also correct? Then just consider any function that isn't onto. Any one. You pick.

 

[iscreamath]

thank you

thanks for the help!