# S.O.S. Mathematics CyberBoard

Your Resource for mathematics help on the web!
 It is currently Sat, 25 May 2013 04:27:36 UTC

 All times are UTC [ DST ]

 Page 1 of 1 [ 3 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Logic/ Statements and QuantifiersPosted: Thu, 10 Mar 2011 16:14:35 UTC

Joined: Wed, 9 Mar 2011 22:13:06 UTC
Posts: 6
Hello!
I have a following problem to solve:

The statement "For SOME real number x, X^2 (x to the second power) is greater or equal to 0" is true.
However, your friend does not understand why, since he claims that X^2 is greater or equal to 0 for ALL real numbers X and not just for SOME. How would you explain his misconception to him?

I know that some means at least one, which makes the first statement true. But on the other hand, I need to agree with this friend because I cannot come with a real number for which this equation would be false. Doesn't is mean that it is true for ALL real numbers then?

Top

 Post subject: Re: Logic/ Statements and QuantifiersPosted: Thu, 10 Mar 2011 18:17:02 UTC
 Moderator

Joined: Wed, 30 Mar 2005 04:25:14 UTC
Posts: 12103
Location: Austin, TX
magwoj wrote:
Hello!
I have a following problem to solve:

The statement "For SOME real number x, X^2 (x to the second power) is greater or equal to 0" is true.
However, your friend does not understand why, since he claims that X^2 is greater or equal to 0 for ALL real numbers X and not just for SOME. How would you explain his misconception to him?

I know that some means at least one, which makes the first statement true. But on the other hand, I need to agree with this friend because I cannot come with a real number for which this equation would be false. Doesn't is mean that it is true for ALL real numbers then?

If it's true for all of them, then it's definitely true for some of them, both statements are true. It's like saying some NBA players know how to play basketball. Surely this is true, it's just also true for all of them. You shouldn't let the fact that you're talking about math make you doubt how logic works, logic is applicable everywhere.

_________________
(\ /)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination

Top

 Post subject: Posted: Fri, 11 Mar 2011 05:04:02 UTC

Joined: Wed, 9 Mar 2011 22:13:06 UTC
Posts: 6
Thank you. I think I was just over-analyzing it too much and I thought there was more to it than that

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: No registered users

 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