Teacher2Teacher

Q&A #849

Teachers' Lounge Discussion: Factoring the sum and difference of two cubes

T2T || FAQ || Ask T2T || Teachers' Lounge || Browse || Search || T2T Associates || About T2T

View entire discussion
[<< prev]

From: Derek

To: Teacher2Teacher Public Discussion
Date: 2009091019:53:56
Subject: Re: Factoring the sum and difference of two cubes

A great way to motivate this is to use synthetic division. For example: x^3-8=0 must have a zero of 2. When we synthetically divide by 2, we get 1 2 4, so x^3-8=(x-2)(x^2+x+4). Doing a couple more examples should make the pattern clear. It can also be generalized by synthetically dividing x^3-a^3 by a (one of its zeros).

Post a reply to this message
Post a related public discussion message
Ask Teacher2Teacher a new question


[Privacy Policy] [Terms of Use]

_____________________________________
Math Forum Home || The Math Library || Quick Reference || Math Forum Search
_____________________________________

Teacher2Teacher - T2T ®
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/