# math equasion **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 12, 2001, 8:26pm UTC](https://boards.straightdope.com/t/math-equasion/75932 "2001-08-12T20:26:19Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![clayton\_e](https://avatars.discourse-cdn.com/v4/letter/c/c57346/32.png) [@clayton\_e](https://boards.straightdope.com/u/clayton_e)\ **Post date:** [August 12, 2001, 8:26pm UTC](https://boards.straightdope.com/t/math-equasion/75932/1 "2001-08-12T20:26:19Z")
try this, it works. x^2 = (x+1)(x-1)+1 ---
**Author:** ![Legomancer](https://avatars.discourse-cdn.com/v4/letter/l/779978/32.png) [@Legomancer](https://boards.straightdope.com/u/Legomancer)\ **Post date:** [August 12, 2001, 8:29pm UTC](https://boards.straightdope.com/t/math-equasion/75932/2 "2001-08-12T20:29:44Z")
It only works for certain values of 1. ---
**Author:** ![clayton\_e](https://avatars.discourse-cdn.com/v4/letter/c/c57346/32.png) [@clayton\_e](https://boards.straightdope.com/u/clayton_e)\ **Post date:** [August 12, 2001, 8:34pm UTC](https://boards.straightdope.com/t/math-equasion/75932/3 "2001-08-12T20:34:06Z")
No, it doesn’t. Try it w/ anything, negative #'s, decimals, and “0”. You are wrong. ---
**Author:** ![DeathLlama](https://avatars.discourse-cdn.com/v4/letter/d/f07891/32.png) [@DeathLlama](https://boards.straightdope.com/u/DeathLlama)\ **Post date:** [August 12, 2001, 8:43pm UTC](https://boards.straightdope.com/t/math-equasion/75932/4 "2001-08-12T20:43:56Z")
don’t know nuthin about that number stuff, but I’m pretty sure equasion is spelled with a “t” where that “s” is. ---
**Author:** ![Strainger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/strainger/32/244_2.png) [@Strainger](https://boards.straightdope.com/u/Strainger)\ **Post date:** [August 12, 2001, 8:46pm UTC](https://boards.straightdope.com/t/math-equasion/75932/5 "2001-08-12T20:46:40Z")
Lessee… x^2=(x-1)(x+1)-1. Using the FOIL method, we get… x^2=x^2+x-x-1-1 x^2=x^2-2 0=-2 Hmmm. Number subsitution doesn’t seem to work either. ---
**Author:** ![iampunha](https://avatars.discourse-cdn.com/v4/letter/i/74df32/32.png) [@iampunha](https://boards.straightdope.com/u/iampunha)\ **Post date:** [August 12, 2001, 8:50pm UTC](https://boards.straightdope.com/t/math-equasion/75932/6 "2001-08-12T20:50:25Z")
> [@](#): > > \*Originally posted by Legomancer \* > \*\*It only works for certain values of 1. \*\* Which values of 1 don’t work?🙂 ---
**Author:** ![kabbes](https://avatars.discourse-cdn.com/v4/letter/k/e99b99/32.png) [@kabbes](https://boards.straightdope.com/u/kabbes)\ **Post date:** [August 12, 2001, 8:52pm UTC](https://boards.straightdope.com/t/math-equasion/75932/7 "2001-08-12T20:52:18Z")
No strainger - her said + 1 (x-1)(x+1) = x^2 - 1 So the equation is correct. Try it with anything you like. eg (0 - 1) (0 + 1) + 1 = (-1)\*1 + 1 = -1 + 1 = 0 pan ---
**Author:** ![Legomancer](https://avatars.discourse-cdn.com/v4/letter/l/779978/32.png) [@Legomancer](https://boards.straightdope.com/u/Legomancer)\ **Post date:** [August 12, 2001, 8:53pm UTC](https://boards.straightdope.com/t/math-equasion/75932/8 "2001-08-12T20:53:47Z")
> [@](#): > > \*Originally posted by iampunha \* > \*\* > > > [@](#): > > > > \*Originally posted by Legomancer \* > > \*\*It only works for certain values of 1. \*\* > > Which values of 1 don’t work?🙂 \*\* The larger ones. As 1 -\> infinity the equation fails. ---
**Author:** ![iampunha](https://avatars.discourse-cdn.com/v4/letter/i/74df32/32.png) [@iampunha](https://boards.straightdope.com/u/iampunha)\ **Post date:** [August 12, 2001, 8:55pm UTC](https://boards.straightdope.com/t/math-equasion/75932/9 "2001-08-12T20:55:17Z")
If you take the “+1” off the end, it works. X^2 + x - x=X^2 the two Xs cancel out, leaving: X^2=X^2. ---
**Author:** ![Manduck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manduck/32/256_2.png) [@Manduck](https://boards.straightdope.com/u/Manduck)\ **Post date:** [August 12, 2001, 8:59pm UTC](https://boards.straightdope.com/t/math-equasion/75932/10 "2001-08-12T20:59:35Z")
> [@](#): > > \*Originally posted by iampunha \* > \*\*If you take the “+1” off the end, it works. > > X^2 + x - x=X^2 > > the two Xs cancel out, leaving: > > X^2=X^2. \*\* You’re leaving off a term - (x+1)(x-1) is x^2+x-x-1 ---
**Author:** ![Strainger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/strainger/32/244_2.png) [@Strainger](https://boards.straightdope.com/u/Strainger)\ **Post date:** [August 12, 2001, 9:00pm UTC](https://boards.straightdope.com/t/math-equasion/75932/11 "2001-08-12T21:00:34Z")
> [@](#): > > \*Originally posted by kabbes \* > \*\*No strainger - her said + 1 > > (x-1)(x+1) = x^2 - 1 > > So the equation is correct. Try it with anything you like. > > eg (0 - 1) (0 + 1) + 1 = (-1)\*1 + 1 = -1 + 1 = 0 > > pan \*\* Crap, you’re right. I knew I shouldn’t have been looking back and forth between the post and the reply window while I was tired. ---
**Author:** ![Slip\_Mahoney](https://avatars.discourse-cdn.com/v4/letter/s/e47774/32.png) [@Slip\_Mahoney](https://boards.straightdope.com/u/Slip_Mahoney)\ **Post date:** [August 12, 2001, 10:21pm UTC](https://boards.straightdope.com/t/math-equasion/75932/12 "2001-08-12T22:21:23Z")
This won’t work in sub-space field harmonics. You’ll just get a transverse polynomial with a sequential tri-phase declination. But I guess everybody knows that. ---
**Author:** ![Chum](https://avatars.discourse-cdn.com/v4/letter/c/3ab097/32.png) [@Chum](https://boards.straightdope.com/u/Chum)\ **Post date:** [August 12, 2001, 10:39pm UTC](https://boards.straightdope.com/t/math-equasion/75932/13 "2001-08-12T22:39:46Z")
I’m kind of confused as to why **clayton\_e** decided to post this in the first place. Yeah, it works. So what? And did s/he spell “equation” incorrectly on purpose? My guess is that s/he is administering a test to see who would try to prove it wrong and sound like a smarty pants. It worked - s/he caught **Strainger** and **iampunha**. Fun. Although I am most definitely not on the same math level as **Slip Mahoney** , I can easily prove that equation to be true using very basic algebraic math skills. We’re talking 7th grade, here. Hmmm… ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [August 12, 2001, 10:45pm UTC](https://boards.straightdope.com/t/math-equasion/75932/14 "2001-08-12T22:45:04Z")
Yeah, I don;t get it. We all know it only works for small values of 1 and we all know it is spelled “equashon” so, what’s the deal? ---
**Author:** ![Lockz](https://avatars.discourse-cdn.com/v4/letter/l/f4b2a3/32.png) [@Lockz](https://boards.straightdope.com/u/Lockz)\ **Post date:** [August 13, 2001, 1:28am UTC](https://boards.straightdope.com/t/math-equasion/75932/15 "2001-08-13T01:28:53Z")
> [@](#): > > \*Originally posted by clayton\_e \* > \*\*try this, it works. > > x^2 = (x+1)(x-1)+1 \*\* Ok, been a few months, but lets try mathematical induction. First, prove x is true for x=1 LS = x^2 RS = (x+1)(x-1)+1 = 1^2 = (1+1)(1-1)+1 = 1 = (2)(0)+1 = 0+1 = 1 Now, let us assume x is true for x=k ie, assume k^2 = (k+1)(k-1)+1 Now, I will try to prove x is true for x=k+1 LS = (k+1)^2 RS = ((k+1)+1)((k+1)-1)+1 = k^2+2k+1 = (k+2)(k)+1 = k^2+2k+1 Since LS=RS, then the equation is true. As said, it has been a while, so I’m not sure if this is right. I remember having to use step number two in number three, but again, not sure. ---
**Author:** ![kabbes](https://avatars.discourse-cdn.com/v4/letter/k/e99b99/32.png) [@kabbes](https://boards.straightdope.com/u/kabbes)\ **Post date:** [August 13, 2001, 8:23am UTC](https://boards.straightdope.com/t/math-equasion/75932/16 "2001-08-13T08:23:47Z")
That only proves it true for positive real integers. pan ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [August 13, 2001, 9:51am UTC](https://boards.straightdope.com/t/math-equasion/75932/17 "2001-08-13T09:51:45Z")
I’m not sure if to take this seriously. Are you guys serious? Can anyone here multiply? (x+1) \* (x-1) = x^2 - x + x - 1 = x^2 -1 Tht is true for any value of x now, x^2 = (x+1)(x-1)+1 is the same as x^2 - 1 = (x+1) \* (x-1) does anyone see a slight similarity? (I feel I must be missing some joke here) ---
**Author:** ![clayton\_e](https://avatars.discourse-cdn.com/v4/letter/c/c57346/32.png) [@clayton\_e](https://boards.straightdope.com/u/clayton_e)\ **Post date:** [August 13, 2001, 6:43pm UTC](https://boards.straightdope.com/t/math-equasion/75932/18 "2001-08-13T18:43:28Z")
Yeah, Chum’s right, that’s why I started this thread, to have a few ppl try to prove that something true is false, and so I can trash them if I see them ever trying to sound smart in any other thread. ---
**Author:** ![Strainger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/strainger/32/244_2.png) [@Strainger](https://boards.straightdope.com/u/Strainger)\ **Post date:** [August 13, 2001, 7:11pm UTC](https://boards.straightdope.com/t/math-equasion/75932/19 "2001-08-13T19:11:20Z")
Well, it looks like your evil scheme has paid off, **clayton\_e**. Thanks to my misreading of your “math equasion,” I no longer hold any credibility on the SDMB. I will be debunked in General Questions, discredited in Great Debates, mocked in IMHO, shunned in MPSIMS, and farted at in the BBQ Pit. Also, my cat will puke on my bedsheets and I’ll develop a screaming case of jock itch. Now, when does school get started again? Soon, isn’t it? Bring some extra cash so you’ll still be able to eat after your lunch money gets stolen. You’ll have to hide it though (hint: rent Papillon).