Register to reply

Basic basic set theory. Please help. Simple answer will suffice.

by andrewkg
Tags: basic, simple, suffice, theory
Share this thread:
andrewkg
#1
Feb20-13, 02:17 AM
P: 86
Hello my name is Andy I'm in highschool, and I have a bit of a confusion or lack of information. Ok so I have been reading a book on set theory, and I keep encountering … ,but up more in the use of a set. Like A,B … but again up more to the middle of the sentence. I feel dumb, I googled it nothing, I've been thinking about it for around 2 hours. I cannot sleep it is bugging me so much. Thank you in advanced!
Phys.Org News Partner Science news on Phys.org
NASA team lays plans to observe new worlds
IHEP in China has ambitions for Higgs factory
Spinach could lead to alternative energy more powerful than Popeye
Simon Bridge
#2
Feb20-13, 03:28 AM
Homework
Sci Advisor
HW Helper
Thanks ∞
Simon Bridge's Avatar
P: 12,406
I keep encountering … ,but up more in the use of a set. Like A,B … but again up more to the middle of the sentence
You mean you keep encountering three dots like this "..." or "##\cdots##"?
They are called "ellipsis" and stand for the words "and so on", and mean that things continue as implied by what went before.

So:
##A,B,\cdots## means start going A B C etc and keep going in the same pattern ... so ##\{ 1,3,5,\cdots \}## would represent the set of positive odd numbers
##\{ 1,3,5,\cdots,27,29 \}## would be all the odd numbers from 1 through to 27 inclusive.
They are written like that because it would be boring to list every single member.

In a sentence it indicates, informally, a longish pause - in a quotation, it means that part of the quote that goes there was deleted for clarity.
At the end of a sentence it indicates that the sentence has been deliberately left unfinished.

See:
http://www.mathsisfun.com/sets/sets-introduction.html
http://en.wikipedia.org/wiki/Ellipsis


Register to reply

Related Discussions
Concept of Distance and time. (basic question but no answer) Introductory Physics Homework 1
Basic basic javascript form validation. literally need an help ASAP Programming & Computer Science 0
Does This Answer Make Sense (basic EM)... Introductory Physics Homework 1
Basic Forces- Just seeking a simple answer Introductory Physics Homework 3
[Basic QM] Potential step & particle flow, my answer is inconsistent...? Advanced Physics Homework 2