Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Please remind me why -3^2 = -9
Replies: 26   Last Post: Nov 18, 2012 7:51 PM

 Messages: [ Previous | Next ]
 Wayne Mackey Posts: 312 Registered: 12/4/04
RE: Please remind me why -3^2 = -9
Posted: Oct 19, 2012 10:50 AM

What if a student has to replace x by 3 in the expression - x^2? Shouldn't he or she know the result?

wayne

________________________________________
From: owner-mathedcc@mathforum.org [owner-mathedcc@mathforum.org] on behalf of Alain Schremmer [schremmer.alain@gmail.com]
Sent: Friday, October 19, 2012 7:19 AM
To: Clyde Greeno
Cc: Philip Mahler; mathedcc
Subject: Re: Please remind me why -3^2 = -9

On Oct 19, 2012, at 12:48 AM, Clyde Greeno wrote:

> In this case, the challenge to the student might be:
> "Below, insert parens to show two reasonable interpretations of
> '-3^2' ... and circle the one that is most commonly used in
> mathematical literature:
> -3^2 or -3^2 "

Very nice!!!
Best regards
--schremmer
****************************************************************************
* To post to the list: email mathedcc@mathforum.org *
* To unsubscribe, email the message "unsubscribe mathedcc" to majordomo@mathforum.org *
* Archives at http://mathforum.org/kb/forum.jspa?forumID=184 *
****************************************************************************
****************************************************************************
* To post to the list: email mathedcc@mathforum.org *
* To unsubscribe, email the message "unsubscribe mathedcc" to majordomo@mathforum.org *
* Archives at http://mathforum.org/kb/forum.jspa?forumID=184 *
****************************************************************************

Date Subject Author
10/18/12 Phil Mahler
10/18/12 John Peterson
10/18/12 Guy Brandenburg
10/18/12 Wayne Mackey
10/18/12 Phil Mahler
10/18/12 RotmanJ
10/18/12 Paul Hertzel
10/18/12 Phil Mahler
10/18/12 Clyde Greeno
10/19/12 Clyde Greeno
10/19/12 Alain Schremmer
10/19/12 Wayne Mackey
10/19/12 Alain Schremmer
10/19/12 Clyde Greeno
10/19/12 Alain Schremmer
10/21/12 Wayne Mackey
11/14/12 Beth Hentges
11/15/12 Clyde Greeno
11/16/12 Alain Schremmer
10/18/12 Collinge, Peter (Mathematics)
10/18/12 Guy Brandenburg
10/18/12 Phil Mahler
10/18/12 Alain Schremmer
11/18/12 EddieC
11/18/12 Matthews, George
11/18/12 Phil Mahler
11/18/12 Alain Schremmer