Teacher2Teacher

Q&A #849


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: Marielouise (for Teacher2Teacher Service)
Date: Nov 29, 1998 at 21:48:08
Subject: Re: Factoring the sum and difference of two cubes

If you are a teacher and wish to show how to do this: Divide (x^3 + y^3) by (x + y) using long division. The answer is: (x^2 - xy + y^2). Similarly divide (x^3 - y^3) by (x - y) and get (x^2 + xy + y^2) If you are a student and wish to learn this I suggest that you learn the pattern: (x^3 + y^3) = (cube root of x^3 + cube root of y^3)((cube root of x^3)^2 - product of the two cube roots + (cube root of y^3)^2) For example: (64 - 27x^6) = (4 - 3x^2)(16 + 12x^2 + 9x^4) Practice some. Marielouise, for the Teacher2Teacher service

Post a 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/