
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
January 5th, 2017, 01:19 PM  #1 
Newbie Joined: Dec 2016 From: England Posts: 1 Thanks: 0  Set Builder Notation?
Hi everybody. I'm currently trying to understand the principles of set builder notation. I understand that "(" is used for < and > and "[" is used for less than or equal to and greater than or equal to. But I am looking at a question which says; "Use set builder notation to give a description of each of these three (3) sets. Assume a domain of integers." I. { 0, 4, 8, 12, 16} II. {−6,−4,−2, 0, 2, 4, 6} It doesn't actually tell me what the condition for the set is though such as "x  x > 4" or something like that so I'm confused as to what the answers to these questions would be. I'm probably missing something so if somebody could help me that that would be much appreciated, thanks. 
January 5th, 2017, 01:33 PM  #2 
Senior Member Joined: Sep 2015 From: CA Posts: 1,238 Thanks: 637 
I. $\{0, 4, 8, 12, 16\} = \{x : x = 4 k,~k \in \mathbb{Z} \wedge 0\leq k \leq 4\}$ II. $\{−6,−4,−2, 0, 2, 4, 6\} = \{x : x=2k,~k\in \mathbb{Z} \wedge 3 \leq k \leq 3\}$ another slightly more elegant way of expressing this is $\{x : x=2k,~k\in \mathbb{Z} \wedge k\leq 3 \}$ 
January 5th, 2017, 02:14 PM  #3 
Global Moderator Joined: May 2007 Posts: 6,235 Thanks: 497 
( and [ are used when referring to continuous sets. Not meaningful for discrete sets.


Tags 
builder, notation, set 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Set Builder to Interval Notation  MathChallenged2010  Algebra  6  March 2nd, 2010 07:41 AM 
tuple builder notation?  random_thinker  Applied Math  26  June 23rd, 2009 07:08 AM 