Factorial of negative numbers?

ILikeTofuuJoe · 2018-09-29 03:05:45

No math geeks probably thought of this.
We'll need a new system of numbers to do this.
Lets say 1/0 = k
Then -1! = k
And -2! would be -k.
-3! = 2k
-4! = -6k and so on.

Freckleface · 2018-09-29 03:21:41

Agreed

ILikeTofuuJoe · 2018-09-29 03:28:50

Freckleface wrote:

Agreed

PLEASE

Ratburntro44 · 2018-09-29 04:20:07

there are good reasons not to do this

RailMat

ILikeTofuuJoe · 2018-09-29 04:40:01

Ratburntro44 wrote:

there are good reasons not to do this

Example please.

HeyNK · 2018-09-29 04:53:15

Already exists

ILikeTofuuJoe · 2018-09-29 04:56:27

HeyNK wrote:

Already exists

0!w would become undefined then

HeyNK · 2018-09-29 05:00:22

0 is not less then 0 tbh

LukeM · 2018-09-29 11:32:53

You just can't give a value to 1/0...

One of the problems is that the rules of fractions say that you can multiply both sides by a value and the fraction will still have the same value. This means that 1/0 = 2/0 = 3/0 etc.
You can then take out the values and say that 1(1/0) = 2(1/0) = 3(1/0), so if there was a value given to it then k = 2k = 3k, and k can't be 0 as 0 * 0 ≠ 1, so k can't just be given a value, and it doesn't help at all with algebra because depending on how you simplify it you can get different numbers of k.

1/0 is basically infinity, but that infinity isn't really useful for anything so we just say you can't divide by 0

Minimania

TaskManager · 2018-09-29 12:13:11

mate quit trying to break maths and bashing on math geeks you certainly will not succeed, not within these forums at least
/thread

LukeM, Latif, pwnzor, drunkbnu

ILikeTofuuJoe · 2018-09-29 15:05:45

Undefined...

hummerz5 · 2018-09-29 16:38:53

LukeM wrote:

1/0 is basically infinity, but that infinity isn't really useful for anything so we just say you can't divide by 0

basically. but we don't know which infinity without more information, so we can't decide.

ILikeTofuuJoe · 2018-09-29 17:38:32

1/0 is an undefined value that should have a special value.

azurepudding · 2018-09-29 20:45:34

LukeM wrote:

You just can't give a value to 1/0...
One of the problems is that the rules of fractions say that you can multiply both sides by a value and the fraction will still have the same value. This means that 1/0 = 2/0 = 3/0 etc.
You can then take out the values and say that 1(1/0) = 2(1/0) = 3(1/0), so if there was a value given to it then k = 2k = 3k, and k can't be 0 as 0 * 0 ≠ 1, so k can't just be given a value, and it doesn't help at all with algebra because depending on how you simplify it you can get different numbers of k.
1/0 is basically infinity, but that infinity isn't really useful for anything so we just say you can't divide by 0

Why would it be infinity?
For the fraction 1/3: If you cut a pie in 3 equal pieces, you have 3 thirds of a pie, with 3/3 being the whole pie.
For the fraction 1/1: In this case you don't cut the pie, as the whole pie is one piece, so 1/1 would be the whole pie.
For the fraction 1/0: If you cut a pie in 0 equal pieces, you.. well, can't do that. You can't have "one zeroth" of the pie, and the whole pie would have to be 0/0 as 1/0 would exceed the number of slices.

With the fraction 1/3, 3 goes into 1 one third of the time, as 1 is a third of 3.
For the fraction 3/1, 1 goes into 3 three times, as 3 is thrice of 1.

With the fraction 0/3, 3 goes into 0 zero times, as 0 is zero times of 3.
But for the fraction 3/0, 0 goes into three an undefined amount of times. Even 0 times infinity won't get you closer to 3- you'd still be at 0. This is why I don't think it can be infinity, as even infinity isn't enough. Not only is no number big enough, but even infinity becomes zero when multiplied by it.

Tomahawk · 2018-09-29 21:39:36

azurepudding wrote:

Why would it be infinity?

Because 1/x approaches infinity as x approaches zero, so you can extrapolate and say that 1/x = infinity when x = 0.

The pie analogy kinda breaks down when x < 1. If you want a visual explanation, have a look at a graph of y = 1/x.

LukeM, hummerz5, SirJosh3917

Minimania · 2018-09-29 21:46:39

I thought zero times infinity was undefined

azurepudding · 2018-09-29 22:19:50

Tomahawk wrote:

azurepudding wrote:
Why would it be infinity?
Because 1/x approaches infinity as x approaches zero, so you can extrapolate and say that 1/x = infinity when x = 0.
The pie analogy kinda breaks down when x < 1. If you want a visual explanation, have a look at a graph of y = 1/x.

That doesn't mean it is tho- and what of my other example? Your point alone I might consider it being true, but I think my example there conflicts with it, as 0 times infinity can't get you 3 or 5 or any other number, besides 0 again.

As for the pie analogy, anything smaller than 1 would just be a smaller slice. If you cut a pie in half, and cut one half in half, you'll have two fourths and one half, but three slices- just different sizes. 1/4 is the same worth as 0.5/2.

I'm not too great with explaining, but a quick google search got me this:

"If you divide 6 by zero, then you are asking the question, "What number times zero gives 6?" The answer to that one, of course, is no number, for we know that zero times any real number is zero not 6. So we say that division by zero is undefined, for it is not consistent with division by other numbers."

If we replace 0 with 3, we get:
6/3=2, and 2*3=6

But with 0:
6/0=x, and 0*x=6

What would x be? Plugging in infinity doesn't seem to work.

minimania wrote:

I thought zero times infinity was undefined

I don't know about that. I see (0 * infinity) as "zero groups of infinity," meaning no infinity, or just zero.

hummerz5 · 2018-09-29 22:31:32

azurepudding wrote:

I don't know about that. I see (0 * infinity) as "zero groups of infinity," meaning no infinity, or just zero.

infinity multiplied by any number is infinity
zero multiplied by any number is zero

ergo, ?

drunkbnu

azurepudding · 2018-09-29 22:46:22

hummerz5 wrote:

azurepudding wrote:
I don't know about that. I see (0 * infinity) as "zero groups of infinity," meaning no infinity, or just zero.
infinity multiplied by any number is infinity
zero multiplied by any number is zero
ergo, ?

I think that first one is a false premise?- zero groups of infinity should be nothing, as you'd have no infinities. It could also be seen as an infinite amount of zeroes being multiplied by each other.. which I suppose would lead to a never-ending equation, but as we know 0x0=0, any further multiplications of 0 would still result in 0.

And isn't infinity * -1 = negative infinity? It's a form of infinity, but that's multiplication of infinity resulting in not infinity.

HeyNK · 2018-09-30 00:21:16

ILikeTofuuJoe wrote:

1/0 is an undefined value that should have a special value.

hahhhhhhahhahahahahahahahaahahah

this guy is the poster boy for "i just learned about complex numbers and I think they're the coolest thing ever wow mind = blown im a math PHD now"

EnanoTLL gets the /thread btw

drunkbnu, TaskManager, ZeldaXD

hummerz5 · 2018-09-30 00:58:26

azurepudding wrote:

hummerz5 wrote:
azurepudding wrote:
I don't know about that. I see (0 * infinity) as "zero groups of infinity," meaning no infinity, or just zero.
infinity multiplied by any number is infinity
zero multiplied by any number is zero
ergo, ?
I think that first one is a false premise?- zero groups of infinity should be nothing, as you'd have no infinities. It could also be seen as an infinite amount of zeroes being multiplied by each other.. which I suppose would lead to a never-ending equation, but as we know 0x0=0, any further multiplications of 0 would still result in 0.
And isn't infinity * -1 = negative infinity? It's a form of infinity, but that's multiplication of infinity resulting in not infinity.

As to that last point, you're correct. I apologize for not acting as the pedant I usually am.

I like the second answer here that says you can't 'physically' add zero an infinite number of times. It's a silly claim, but it seems acceptable.

Also, given the formal definition of factorial, I don't think we should settle for the gamma representation to make any sort of argument about what it would be as a negative. It simply isn't.

Tomahawk · 2018-09-30 01:00:23

Pls stop trying to apply logic to infinity and other undefined values. It doesn’t work.

hummerz5

Official Everybody Edits Forums

#1 2018-09-29 03:05:45

Factorial of negative numbers?

#2 2018-09-29 03:21:41

Re: Factorial of negative numbers?

#3 2018-09-29 03:28:50

Re: Factorial of negative numbers?

#4 2018-09-29 04:20:07

Re: Factorial of negative numbers?

#5 2018-09-29 04:40:01

Re: Factorial of negative numbers?

#6 2018-09-29 04:53:15

Re: Factorial of negative numbers?

#7 2018-09-29 04:56:27

Re: Factorial of negative numbers?

#8 2018-09-29 05:00:22

Re: Factorial of negative numbers?

#9 2018-09-29 11:32:53, last edited by LukeM (2018-09-29 11:33:11)

Re: Factorial of negative numbers?

#10 2018-09-29 12:13:11

Re: Factorial of negative numbers?

#11 2018-09-29 15:05:45

Re: Factorial of negative numbers?

#12 2018-09-29 16:38:53

Re: Factorial of negative numbers?

#13 2018-09-29 17:38:32

Re: Factorial of negative numbers?

#14 2018-09-29 20:45:34

Re: Factorial of negative numbers?

#15 2018-09-29 21:39:36

Re: Factorial of negative numbers?

#16 2018-09-29 21:46:39

Re: Factorial of negative numbers?

#17 2018-09-29 22:19:50, last edited by azurepudding (2018-09-29 22:26:01)

Re: Factorial of negative numbers?

#18 2018-09-29 22:31:32

Re: Factorial of negative numbers?

#19 2018-09-29 22:46:22

Re: Factorial of negative numbers?

#20 2018-09-30 00:21:16

Re: Factorial of negative numbers?

#21 2018-09-30 00:58:26

Re: Factorial of negative numbers?

#22 2018-09-30 01:00:23

Re: Factorial of negative numbers?

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