## Show us your math genius

If it doesn't fit elsewhere, it should go here JWinslow23
Posts: 139
Joined: 06 Feb 2013, 01:05
An alternate formula for phi:

Code: Select all

``````         ________
/  __
/ \/45+5
\    / --------
\  /      __
\/     \/20``````
Phi is the golden ratio, the sum of 1 and the square root of 5 divided by 2,

Code: Select all

``````    _
1+\/5
-----
2``````
I found that out myself!

Do you have any mathematical oddities to share? Firaga
Posts: 931
Joined: 02 Jul 2012, 16:05

Code: Select all

``2 + 2 = 5`` HansAgain
Posts: 1103
Joined: 03 Feb 2012, 18:51
Firaga41 wrote:

Code: Select all

``2 + 2 = 5``
Just amazing.  Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00

Code: Select all

``x = 0``

Code: Select all

``x + x = x``
Add x to both sides

Code: Select all

``2x = x``
Combine like terms

Code: Select all

``2 = 1``
Divide by X
(Originally by someone else from here)
Last edited by Qcode on 07 May 2013, 00:16, edited 1 time in total. Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
(Accidental double post)
Last edited by Qcode on 07 May 2013, 00:15, edited 1 time in total.

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
This thread is awful and you should feel bad about making it.

And I'm not even joking here this is just an utterly awful thread.
also hi qcode that was mine BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
Qcode wrote:

Code: Select all

``x = 0``
Divide by X
My genius, divide by 0 error. :P

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
Novice mistake there Bob, it's actually fine to divide by X there, no matter what value it has, because both sides contain X so you're just cancelling it out of the equation. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
No... It... It can't be true... Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
The real problem is when you add to both sides.

Code: Select all

``x + x = 0 + x``
Since x = 0, it should be simplified to

Code: Select all

``x + x = x + x`` popcan12
Posts: 592
Joined: 10 Feb 2012, 02:30
64+64x2x2= 320
...I can't live anymore.
Last edited by popcan12 on 07 May 2013, 01:41, edited 1 time in total.

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
popcan12 wrote:64+64x2x2= 512
Wrong.

If you're "trolling herp derp sarcasms" you're pretty bad at it. popcan12
Posts: 592
Joined: 10 Feb 2012, 02:30
Wrong why? Is it because there's no spaces?

Edit: Just realized, you're right, I forgot order of operations... rokit
Posts: 2095
Joined: 03 Feb 2012, 00:47
(it's not that hard to just go on google)  totally made it myself popcan12
Posts: 592
Joined: 10 Feb 2012, 02:30
Rokit boy wrote:(It's not that hard to just go on google).  Totally made it myself.
Yes, totally Mr. Wikimedia. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
x = 3 TheJonyMyster
Posts: 1795
Joined: 03 Sep 2012, 05:12
22/7 isn't actually pi.
*gasp* Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
Its actually only 3.14 that matches with both. Also it's a basic law of math that irrational numbers can't be expressed as fractions. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
There is no fraction to represent .999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999...
At least in my logic, which would make it the only repeating number without a fraction (though if you added any Integer, it would still probably not be able to be a fraction.)

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
Here's a fraction to represent it:

1/1 Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
BobTheLawyer wrote:There is no fraction to represent .999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999...
A consistent repeating number doesn't count as an irrational number. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
I didn't say it was an irrational number, and Camewel, those aren't equivalent. Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
He's right.

Code: Select all

``x = .999999...``
Therefore

Code: Select all

``10x = 9.99999999...``
Now subtract x from both sides of the previous equation.

Code: Select all

``9x = 9.999999... - .9999999...``

Code: Select all

``9x = 9``
Divide by 9.

Code: Select all

``x = 1``
.9 repeating = 1. Automatik
Posts: 1073
Joined: 20 Jul 2012, 17:54

Code: Select all

``````x=1/3
x=0.33333333333...
x=x*3
x=0.99999999999...
x=(1/3)*3
x=3/3
x=1
`````` BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
Qcode wrote:He's right.

Code: Select all

``10x = 9.99999999...``
Now subtract x from both sides of the previous equation.

Code: Select all

``9x = 9.999999... - .9999999...``
You must keep like terms!!!
9x - .999999... = 9
Anyways, in your theory, it should be,
9.000...1x = 9
No rounding in math!!!

Code: Select all

``````x=1/3
x=0.33333333333...
x=x*3
x=0.99999999999...
x=(1/3)*3
x=3/3
x=1
``````
You are forgetting why 1/3 = .333333...
Because you are slicing 1 into 3 parts.
It cannot truly equal .333333333333333333333333333333333333333333333333333333333333333333333333 or whatever because it goes infinetly small. Never to a four, but always bigger and bigger.
This is so when it combines with 2/3, which = .66666...
It equals 1
If you added up the numbers, you should get .999999999999999999999999999999999999999999..., but that destroys the value of 1/3 and reduces it.
You can never truly put a decimal for 1/3, without increasing or decreasing its value.
.3333333... is symbolizing how it goes infinitely on.
.99999999999999999... would be the number you would start on if I said x < 1
By putting .999999... = 1, you would therefore obliterate the difference between < and <= Automatik
Posts: 1073
Joined: 20 Jul 2012, 17:54
" but that destroys the value of 1/3 and reduces it."
No, why?
Also, there is a wikipedia article on it.
In mathematics, the repeating decimal 0.999... (sometimes written with more or fewer 9s before the final ellipsis, or as 0.9, , 0.(9)) denotes a real number that can be shown to be the number one. In other words, the symbols "0.999..." and "1" represent the same number. Proofs of this equality have been formulated with varying degrees of mathematical rigor, taking into account preferred development of the real numbers, background assumptions, historical context, and target audience.
Last edited by Automatik on 10 May 2013, 21:47, edited 1 time in total. JWinslow23
Posts: 139
Joined: 06 Feb 2013, 01:05 Before I root you, are you over 18?

If the expression equals 0, u=0.

If the expression does not equal 0,there is no solution. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
This doesn't make any sense...
This totally defeats the difference between < and <=... Automatik
Posts: 1073
Joined: 20 Jul 2012, 17:54
Again, why?
Since .999999999999999999999999... is 1.
There is really no difference between the two numbers.
1-.99999999999999999...=0.00000000000000000000000000...=0 BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
Because. Then you loose the concept of being infinitely close, without being equal. Qcode
Posts: 1472
Joined: 05 Feb 2012, 18:00
And how does that effect the less than or equal to statement. Just assume that .9 repeating = 1 and anything less than .9 repeating is less than 1. Automatik
Posts: 1073
Joined: 20 Jul 2012, 17:54
infinitely close=equal
And again, it has been proven BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
I defy math rokit
Posts: 2095
Joined: 03 Feb 2012, 00:47
if you cut 1 into 3 equal parts all of them will be .33 recurring.
so 0.33 * 3 recurring should be 1.

yet if you think about it at first 0.99.. recurring can't be equal to 1 because it will 0.00..001 away from it.

yet, math always proves itself wrong. there are theories about 1 being equal to 2 and such.

Code: Select all

``````a and b are equal and are both non zero values
so if a = b then
aa = ab
or
a² = ab
a² - b² = ab - b² because it's still balanced
so (a-b)(a+b) = b(a-b) (factorize)
divide out (a-b) leaves us with a+b = b and since a = b, b+b = b
so 2b = b
divide by b
2 = 1 ``````
yet substituting that with numbers

Code: Select all

``````1=1
1² = 1*1
1² - 1² = 1*1 - 1² still balanced
(1-1)*(1+1) = 1*(1-1) so basically 0=0 so far so it makes sense
since the next step is divide out (a-b) we have run into a problem, because it will always be zero.
continuing...
(1+1) = 1
2 = 1
``````
i dunno man, maths TheSeek
Posts: 486
Joined: 21 Mar 2012, 06:31
rokit boy wrote: yet, math always proves itself wrong. there are theories about 1 being equal to 2 and such.

Code: Select all

``````a and b are equal and are both non zero values
so if a = b then
aa = ab
or
a² = ab
a² - b² = ab - b² because it's still balanced
so (a-b)(a+b) = b(a-b) (factorize)
divide out (a-b) leaves us with a+b = b and since a = b, b+b = b
so 2b = b
divide by b
2 = 1 ``````
yet substituting that with numbers

Code: Select all

``````1=1
1² = 1*1
1² - 1² = 1*1 - 1² still balanced
(1-1)*(1+1) = 1*(1-1) so basically 0=0 so far so it makes sense
since the next step is divide out (a-b) we have run into a problem, because it will always be zero.
continuing...
(1+1) = 1
2 = 1
``````
i dunno man, maths
uhm...
rokit boy wrote: yet if you think about it at first 0.99.. recurring can't be equal to 1 because it will 0.00..001 away from it.
if it will 0.000..001 away from it, then it's 0.99...9998, not 0.999...

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
There is no such thing as being infinitely close to but not equal with real numbers. With real numbers, there is always another number between two given numbers. If there is no number between the two numbers, then the two numbers have to be equal. Watch this video I don't have the effort to convince you properly.

Also, this thread was meant to be "show off your maths genius" not "display your incompetence" so Bob you're doing it wrong. BobTheLawyer
Posts: 2232
Joined: 01 May 2012, 21:00
Camewel wrote:Also, this thread was meant to be "show off your maths genius" not "display your incompetence" so Bob you're doing it wrong.
:( rokit
Posts: 2095
Joined: 03 Feb 2012, 00:47
TheSeek wrote:
rokit boy wrote: yet, math always proves itself wrong. there are theories about 1 being equal to 2 and such.

Code: Select all

``````a and b are equal and are both non zero values
so if a = b then
aa = ab
or
a² = ab
a² - b² = ab - b² because it's still balanced
so (a-b)(a+b) = b(a-b) (factorize)
divide out (a-b) leaves us with a+b = b and since a = b, b+b = b
so 2b = b
divide by b
2 = 1 ``````
yet substituting that with numbers

Code: Select all

``````1=1
1² = 1*1
1² - 1² = 1*1 - 1² still balanced
(1-1)*(1+1) = 1*(1-1) so basically 0=0 so far so it makes sense
since the next step is divide out (a-b) we have run into a problem, because it will always be zero.
continuing...
(1+1) = 1
2 = 1
``````
i dunno man, maths
uhm...
rokit boy wrote: yet if you think about it at first 0.99.. recurring can't be equal to 1 because it will 0.00..001 away from it.
if it will 0.000..001 away from it, then it's 0.99...9998, not 0.999...
1) i have no idea why you pointed it out that i got it from the internet. wasn't it so obvious?
2) im assuming that 0.99... is not equal to 1. also, 0.99..998 + 0.00..001 = 0.99...

Camewel
Posts: 2996
Joined: 02 Feb 2012, 21:32
0.999999... is equal to one though. That's like saying "I'm assuming 1/2 isn't equal to 2/4" it's garbage and meaningless. TheSeek
Posts: 486
Joined: 21 Mar 2012, 06:31
rokit boy wrote: 1) i have no idea why you pointed it out that i got it from the internet. wasn't it so obvious?
clearly you didnt read what it was in the link...i pointed out that the logic you used has fallacies, and that link shows why
rokit boy wrote: 2) im assuming that 0.99... is not equal to 1. also, 0.99..998 + 0.00..001 = 0.99...
failing hard at simple math...
0.999...9998 is not a repeating decimal cuz in this case the 9 doesnt repeat endlessly(like a repeating decimal would) cuz it ends in 8. So 0.99..998 + 0.00..001 = 0.99(a definite decimal), not 0.99...(a repeating decimal), which is very different.