Go Back   Computer Forums > Welcome To Computer Forums .org > Social Lounge | Off Topic
Click Here to Login
Join Computer forums Today


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-04-2007, 10:46 PM   #1
Daemon Poster
 
ericf1993's Avatar
 
Join Date: Nov 2005
Posts: 671
Default small math problem

i have a small math problem that i dont get. its a^4-2a^2+1 your suppose to factor that completely. the answer is (a+1)(a+1)(a-1)(a-1) but i dont know how that is. can anyone show me a step by step on how to solve this?
__________________

ericf1993 is offline   Reply With Quote
Old 07-04-2007, 10:50 PM   #2
Fully Optimized
 
Join Date: Dec 2005
Posts: 2,276
Default Re: small math problem

um.. can i just ask first, are you learning about derivatives yet?
__________________

__________________
| AMD 3800+ X2 Dual Core Processor | ASUS A8N-e nF4 Ultra | Hitachi Deskstar 250gb 3.0 gb/s | 1gb Corsair Value RAM 2x512 | eVGA geforce 6800GS | sound blaster live! 24-bit | NZXT Trinity Classic chassis | OCZ GameXStream OCZ700GXSSLI PSU |
I was there. In the networking forum for the first time, and it was because.. of 341
kchi55 is offline   Reply With Quote
Old 07-04-2007, 11:06 PM   #3
Daemon Poster
 
ericf1993's Avatar
 
Join Date: Nov 2005
Posts: 671
Default Re: small math problem

no sorry its just suppose to be simple factoring. this is algebra 1 by the way.
ericf1993 is offline   Reply With Quote
Old 07-04-2007, 11:20 PM   #4
Fully Optimized
 
troy's Avatar
 
Join Date: Jul 2006
Location: USA
Posts: 2,410
Default Re: small math problem

hmm... I haven't done this in awhile but I don't think that (a+1)(a+1)(a-1)(a-1) is the right answer.

The problem: a^4-2a^2+1 is easy to factor. All you do is find what the powers have in common. They both have a power of 2, so you'd factor out A^2.
After A^2 is factored out, you'd get A^2(A^2 -2 + 1) and then you solve -2+1 and that's it. I'm kinda tired and I'm not sure that's completely right since it's been awhile since I've done factoring, but I think that's how to do it.
__________________
Desktop: Dell Dimension E510, 2.5GB RAM, Intel P4 3.0GHZ, 250GB HDD, Windows Vista Premium. Might not be the best, but the old girl is still running good.
troy is offline   Reply With Quote
Old 07-04-2007, 11:24 PM   #5
Golden Master
 
freestyler105's Avatar
 
Join Date: Sep 2006
Posts: 7,883
Default Re: small math problem

No, I'm pretty sure that's wrong troy because you can't pull aČ out of 1.

I'm not sure how to do it...I think you'd have to pull out aČ, which gets you aČ(aČ-2)+1...but that doesn't factor any farther.
__________________
C2D E6600 | 4GB DDR2-800 | 9800GTX+ | Asus P5B-E | 150GB Raptor | 320GB 7200.10 | 750W Xigmatek PSU
freestyler105 is offline   Reply With Quote
Old 07-04-2007, 11:27 PM   #6
Daemon Poster
 
ericf1993's Avatar
 
Join Date: Nov 2005
Posts: 671
Default Re: small math problem

well the original book does say that (a+1)(a+1)(a-1)(a-1) is the right answer
ericf1993 is offline   Reply With Quote
Old 07-04-2007, 11:28 PM   #7
Daemon Poster
 
ericf1993's Avatar
 
Join Date: Nov 2005
Posts: 671
Default Re: small math problem

Quote:
Originally Posted by freestyler105 View Post
No, I'm pretty sure that's wrong troy because you can't pull aČ out of 1.

I'm not sure how to do it...I think you'd have to pull out aČ, which gets you aČ(aČ-2)+1...but that doesn't factor any farther.
how do you type exponents?
ericf1993 is offline   Reply With Quote
Old 07-04-2007, 11:28 PM   #8
Fully Optimized
 
troy's Avatar
 
Join Date: Jul 2006
Location: USA
Posts: 2,410
Default Re: small math problem

Quote:
Originally Posted by freestyler105 View Post
No, I'm pretty sure that's wrong troy because you can't pull aČ out of 1.

I'm not sure how to do it...I think you'd have to pull out aČ, which gets you aČ(aČ-2)+1...but that doesn't factor any farther.
Yeah you're right. Like I said, it's been awhile since I've done this. I haven't done algebra in awhile, but hey it doesn't hurt to give it a shot right? Sorry I can't help more... boy it's amazing how quick algebra leaves your mind. It's been about a year since I had this stuff and I've already forgotten a lot of it.

ericf1993,
I'd like to know how to type exponents too. I always use the carrot ^ but that gets confusing sometimes.
__________________
Desktop: Dell Dimension E510, 2.5GB RAM, Intel P4 3.0GHZ, 250GB HDD, Windows Vista Premium. Might not be the best, but the old girl is still running good.
troy is offline   Reply With Quote
Old 07-04-2007, 11:32 PM   #9
Golden Master
 
freestyler105's Avatar
 
Join Date: Sep 2006
Posts: 7,883
Default Re: small math problem

Haha yeah, don't worry about it..

@eric - I used the character map:
- Start
- Program Files
- Accessories
- System Tools
- Character Map


I got this from some website:
Quote:
Simplifying
a^4 + -2a^2 + 1

Reorder the terms:
1 + -2a^2 + a^4

Factor a trinomial.
(1 + -1a^2)(1 + -1a^2)

Factor a difference between two squares.
((1 + a)(1 + -1^a))(1 + -1a^2)

Factor a difference between two squares.
((1 + a)(1 + -1a))(1 + a)(1 + -1a)

Final result:
(1 + a)(1 + -1a)(1 + a)(1 + -1a)
__________________
C2D E6600 | 4GB DDR2-800 | 9800GTX+ | Asus P5B-E | 150GB Raptor | 320GB 7200.10 | 750W Xigmatek PSU
freestyler105 is offline   Reply With Quote
Old 07-05-2007, 12:09 AM   #10
Daemon Poster
 
ericf1993's Avatar
 
Join Date: Nov 2005
Posts: 671
Default Re: small math problem

can your really do that with all the problems that are like this?
__________________

ericf1993 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -5. The time now is 05:17 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.6.0