Computer Forums small math problem

 07-04-2007, 09:46 PM #1 Daemon Poster     Join Date: Nov 2005 Posts: 671 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? __________________ __________________
 07-04-2007, 09:50 PM #2 Fully Optimized   Join Date: Dec 2005 Posts: 2,276 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
 07-04-2007, 10:06 PM #3 Daemon Poster     Join Date: Nov 2005 Posts: 671 Re: small math problem no sorry its just suppose to be simple factoring. this is algebra 1 by the way. __________________
 07-04-2007, 10:20 PM #4 Fully Optimized     Join Date: Jul 2006 Location: USA Posts: 2,410 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.
 07-04-2007, 10:24 PM #5 Golden Master     Join Date: Sep 2006 Posts: 7,883 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
 07-04-2007, 10:27 PM #6 Daemon Poster     Join Date: Nov 2005 Posts: 671 Re: small math problem well the original book does say that (a+1)(a+1)(a-1)(a-1) is the right answer __________________
07-04-2007, 10:28 PM   #7
Daemon Poster

Join Date: Nov 2005
Posts: 671
Re: small math problem

Quote:
 Originally Posted by freestyler105 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?
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07-04-2007, 10:28 PM   #8
Fully Optimized

Join Date: Jul 2006
Location: USA
Posts: 2,410
Re: small math problem

Quote:
 Originally Posted by freestyler105 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.
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07-04-2007, 10:32 PM   #9
Golden Master

Join Date: Sep 2006
Posts: 7,883
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)
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 07-04-2007, 11:09 PM #10 Daemon Poster     Join Date: Nov 2005 Posts: 671 Re: small math problem can your really do that with all the problems that are like this? __________________ __________________