# S.O.S. Mathematics CyberBoard

Your Resource for mathematics help on the web!
 It is currently Tue, 21 May 2013 16:06:12 UTC

 All times are UTC [ DST ]

 Page 1 of 1 [ 3 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: |a - b| = |b - a|Posted: Sun, 13 Sep 2009 21:30:22 UTC
 S.O.S. Oldtimer

Joined: Fri, 18 Jul 2008 01:21:42 UTC
Posts: 147
Location: California, USA
Hello,

I need to prove |a - b| = |b - a|. What I got so far is ||a| + |-b||. I need to have some more steps before proving the consequent is equal to the antecedent but I don't know how to do the intermediate steps. Could someone give me a hint or two?

Thank you,

_________________
Susan

Top

 Post subject: Re: |a - b| = |b - a|Posted: Sun, 13 Sep 2009 22:12:42 UTC
 Member of the 'S.O.S. Math' Hall of Fame

Joined: Wed, 1 Oct 2003 04:45:43 UTC
Posts: 9632
Susan123456 wrote:
I need to prove |a - b| = |b - a|

There are three cases:

(1) a = b, in which case a - b = b - a = 0.

(2) a < b, in which case a - b < 0 and b - a > 0.

(3) a > b, in which case a - b > 0 and b - a < 0.

Top

 Post subject: Posted: Mon, 14 Sep 2009 02:49:27 UTC
 S.O.S. Oldtimer

Joined: Fri, 18 Jul 2008 01:21:42 UTC
Posts: 147
Location: California, USA
thank you very much

_________________
Susan

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 3 posts ]

 All times are UTC [ DST ]

#### Who is online

Users browsing this forum: Mark T

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forum

Search for:
 Jump to:  Select a forum ------------------ High School and College Mathematics    Algebra    Geometry and Trigonometry    Calculus    Matrix Algebra    Differential Equations    Probability and Statistics    Proposed Problems Applications    Physics, Chemistry, Engineering, etc.    Computer Science    Math for Business and Economics Advanced Mathematics    Foundations    Algebra and Number Theory    Analysis and Topology    Applied Mathematics    Other Topics in Advanced Mathematics Other Topics    Administrator Announcements    Comments and Suggestions for S.O.S. Math    Posting Math Formulas with LaTeX    Miscellaneous