Mindscrew

[Horizon]

Just follow along.
X=1;Y=1
2(x^2-y^2)=0
5(x-y)=0
2(x^2-y^2)=5(x-y)
[2(x^2-y^2)=5(x-y)]/(x-y)
2(x+y)=5
2((1)+(1))=5
2(2)=5
Crazy, ain't it?

[Elensaar]

Careful!

Spoiler

Show

You might just cause a black hole with that divide by 0. ;)

[Katalliaan]

Your fifth line has a division by zero (x-y). I've seen that "solution" before, and that one line invalidates the whole thing.

[Zhil]

Haha, I used to create these mind warps all the time when I was 14. I had a pretty cool one where I'd use algebra on one side to end up with a formula and geometry on the other side to end up with a formula. Both abused a quirk to get a different result. If you added them together, you got 1 = 2.

That one was fun to fix and baffled a few students for a while :)

[Horizon]

Would you mind typing the formula out?

[Zhil]

Would you mind typing the formula out?

This was 12 years ago. I remember that the algebra one abused the division by zero like yours does. I might try to figure out a new one though :)

[Horizon]

Yes! I have figured out the approximate age of Gil!
PS: For those of you who suck at reading the whole thread, he said that he did something at age 14, and said that said something was 12 years ago.
PSS: For those of you who suck at math, he's about 26.

[Zhil]

Ah!

http://en.wikipedia.org/wiki/Mathematical_fallacy

Take two proofs out of this one, combine the results in such a way that it produces the fallacy. If done properly, this can really screw people's minds. By doubling the fallacies and doubling the layer of redirection, finding only one fault will still not explain the fallacy.

I'll try to write a new one perhaps, so much fun :)

Yes! I have figured out the approximate age of Gil!
PS For those of you who suck at math, he said that he did something at age 14, and said that said something was 12 years ago.

My name's Simon Meskens, I'm 26 and I'm from Belgium. A cursory google search and you'd have found that. I don't value my identity or privacy.

[walker_boh_65]

PSS: For those of you who suck at math, he's about 26.

PSSS: Sorry to burst your bubble, but he has openly told us his age.

EDIT: and Gil or Simon, beat me to it.

[Horizon]

...dammit.

[Xekrom337]

try this!

i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
i^2 = i^4
-1 = 1

D:

[Donzaffi]

try this!

i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
i^2 = i^4
-1 = 1

D:

i stands in complex numbers for -1 but how many people had touch complex numbers ?

[Horizon]

I must be honest, I'ven't a damned clue what the hell that equation means.

[Dark_Tundra]

try this!

i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
i^2 = i^4
-1 = 1

D:

I think you mean:
i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
±i^2 = ±i^4
±1 = ±1

[Zhil]

I think you mean:
i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
±i^2 = ±i^4
±1 = ±1

Yeah Xekrom, that one isn't really hard to figure out, is it? It's just a blatant mistake :p

For it to work, you need a layer of redirection too.

[Sarudak]

The division by zero trick is classic but not nearly as mind warping as the trick where you can prove that 2=1 using summations of infinite sequences... That one really blew my mind...

[Xekrom337]

I think you mean:
i = sqrt(-1)
i^4 = 1
i^4*i^4 = i^8 = 1
i^4 = i^8
sqrt(i^4) = sqrt(1^8)
±i^2 = ±i^4
±1 = ±1

Yeah Xekrom, that one isn't really hard to figure out, is it? It's just a blatant mistake :p

For it to work, you need a layer of redirection too.

ah, i've been trying to figure out what was wrong with that for a year or so now, but couldn't figure what it was. even my math teacher couldn't figure it out. ah well, back to the drawing board. :P

[MoRmEnGiL]

Spoiler

Show

[jorgebonafe]

Spoiler

Show

[Xekrom337]

try this:

Code: Select all

1/9 * 9 = 0.111111.... * 9 = 0.999999...
9/9 = 1

let x = 1/9 * 9 = 0.111111.... * 9 = 0.999999...
10x = 9.999999...
10x - x = 9 (knock off the reccuring things!)
9x = 9
x = 1

therefore x = 1/9 * 9 = 0.111111.... * 9 = 0.999999... = 1
then
0.999999... = 1
99.999999 = 100

so 0 followed by a infinite number of 9's is eqaul to 1 D:

and another!

Code: Select all

there is an infinite number of oradnary numbers:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20...
then reason states that there is half as many odd numbers as all the numbers:
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39...

How many odd numbers are there in a ratio to normal numbers?

Spoiler

Show

no, its not half!

i like mindscrewing maths :D

[mr.creeper]

try this:

Code: Select all

1/9 * 9 = 0.111111.... * 9 = 0.999999...
9/9 = 1

let x = 1/9 * 9 = 0.111111.... * 9 = 0.999999...
10x = 9.999999...
10x - x = 9 (knock off the reccuring things!)
9x = 9
x = 1

therefore x = 1/9 * 9 = 0.111111.... * 9 = 0.999999... = 1
then
0.999999... = 1
99.999999 = 100

so 0 followed by a infinite number of 9's is eqaul to 1 D:

and another!

Code: Select all

there is an infinite number of oradnary numbers:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20...
then reason states that there is half as many odd numbers as all the numbers:
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39...

How many odd numbers are there in a ratio to normal numbers?

Spoiler

Show

no, its not half!

i like mindscrewing maths :D

I thought it was already proved that 0.99999999...=1.

[Horizon]

I thought it was proven that complex, borderline paradoxical math was bad for your sanity.

[Xekrom337]

I thought it was proven that complex, borderline paradoxical math was bad for your sanity.

i do this kind of thing with my brother all the time. i'm not crazy though...

















...yet.

something else!:

Code: Select all

-i = -1 * sqrt(-1)
i^3 = sqrt(-1) * sqrt(-1) * sqrt(-1) = -1 * sqrt(-1)
-i = i^3
-i * i = i^4
-i^2 = i^4
sqrt(-i^2) = ±i^2     //[sqrt()] and [^2] cancel each other out!
-i = ±i^2
-1 * i = ±1 * -1     //[±1 * stuff] works right? and [i^2 = -1]!
i = ±1
i = sqrt(-1)
sqrt(-1) = ±1

yay! new mindscrew! anyone find a solution/error? because i cant!

[Dark_Tundra]

-i = -1 * sqrt(-1)
i^3 = sqrt(-1) * sqrt(-1) * sqrt(-1) = -1 * sqrt(-1)
-i = i^3
-i * i = i^4
-i^2 = i^4
sqrt(-i^2) = ±i^2 //[sqrt()] and [^2] cancel each other out! (You can't do that to a negative number, negatives can't take[sqrt()], [^2] cancels out the negative)
±i = ±i^2 (Cancelled out or not it needs a ±)

(I've no clue what you are doing below here)
-1 * i = ±1 * -1 //[±1 * stuff] works right? and [i^2 = -1]! (if you are going to start manipulating numbers with ±, you really should split it into 2 equations, one with "+" one with "-")
i = ±1
i = sqrt(-1)
sqrt(-1) = ±1

[Zhil]

Haha Xekrom, you have to brush up on your math :D