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Thread 16836585

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Anonymous No.16836585 [Report] >>16836590 >>16836601 >>16836653 >>16836672 >>16836768 >>16836897 >>16837046 >>16837101 >>16837370 >>16837382 >>16837638 >>16837790 >>16838925 >>16839027 >>16839741
why is division by zero undefined rather than indeterminate? is it purely historical or is there a reason:
>this expression is valid, but there is nothing that satisfies it
doesn't work here?
Anonymous No.16836590 [Report] >>16836673 >>16838161 >>16838841
>>16836585 (OP)
Because if you give division by 0 any value, it breaks math. There's no value to be undetermined, it simply cannot exist
Anonymous No.16836601 [Report] >>16836673
>>16836585 (OP)
>>this expression is valid
It is not.
Division by zero does not satisfy the conditions necessary for division to even take place.
Anonymous No.16836652 [Report]
You can define your own superset of R that allows DIV/0.
Now
Fuck
Off
Anonymous No.16836653 [Report]
>>16836585 (OP)
[math] f(x) = \frac{3x}{x} [/math] vs [math] g(x) = \frac{2x}{x} [/math]. Both f(0) and g(0) look like 0/0, so they're the same right? Then why does f(x) always look like 3 and g(x) always look like 2 for any other x? Sounds like a contradiction if you don't know much math. What's the actual explanation?
Anonymous No.16836672 [Report] >>16836711 >>16836780
>>16836585 (OP)
Context matters in this situation.
In the simple y = 1/x example, are you approaching from x>0 and decreasing, or are you approaching from x<0 and increasing. You choice matters.
Any of you say, "but wut if x=0" without context will receive a mark.
Anonymous No.16836673 [Report] >>16836687 >>16836711 >>16837010
>>16836590
>There's no value to be undetermined, it simply cannot exist
But 'undefined' isn't a way to indicate a value doesn't exist, it precedes existence/non-existence itself. You can't assign properties to an undefined expression like "exists" and "does not exist". That's just more undefined nonsense.

>>16836601
>Division by zero does not satisfy the conditions necessary for division to even take place.
Because it was explicitly defined that way. I'm questioning that we needed to define it that way to begin with.
Anonymous No.16836687 [Report] >>16836707 >>16836711 >>16836718
>>16836673
No, undefined means that the operation is not defined. You can't perform that operation. Indeterminate means that the operation is valid and a value exists, it just can't be determined
Anonymous No.16836707 [Report] >>16836718
>>16836687
'Defined' and 'undefined' precede operations. They precede any kind of reasoning what-so-ever, and exist at the grammar level. They are a description of a collection of symbols, not values and not operations. In other words, there is no 'operation' in 'X/0'. It never even reaches the conceptual space where 'operations' even make sense.
Anonymous No.16836711 [Report]
>>16836672
>>16836673
These two guys are saying the same thing.
>>16836687
This guy just prefers his vocabulary term over theirs.
Anonymous No.16836718 [Report]
>>16836687
>>16836707
The function f(x) = 1/x is undefined at x=0.
You two clowns need to stfu.
Anonymous No.16836768 [Report] >>16836770 >>16836773 >>16836776 >>16836834
>>16836585 (OP)
0 is an absorptive element, so n*0=0, arithmetic doesn't like it when you give absorptive element an inverse such that it*the absorptive=something other than the absorptive,
Anonymous No.16836770 [Report] >>16836776 >>16836778
>>16836768
Clearly repulsive. Again, see y = 1/x.
Anonymous No.16836773 [Report] >>16836776
>>16836768
also it is like extra fucky for the case of 0, since the most common "inverse"(as in 1/0) for 0, inf, is also absorptive
Anonymous No.16836776 [Report]
>>16836768
>>16836770
>>16836773
0 is monopole, confirmed.
Anonymous No.16836778 [Report] >>16836791
>>16836770
who the fuck speaking about limits?
Anonymous No.16836780 [Report] >>16836793 >>16836804 >>16839055 >>16839066
>>16836672
1/0 is obviously 0 though
if you divide 1L of water amongst 0 people each of them gets 0 L since nobody got any water
Anonymous No.16836791 [Report]
>>16836778
>the rock is self-attractive
>look for yourself!
>see? see!
Yes, Anon. 0=0. And we agree that your solution is "stable".
Anonymous No.16836793 [Report]
>>16836780
Each and every last one of them drank all of the water, Anon.
Anonymous No.16836804 [Report] >>16837081
>>16836780
A wandering prophet roamed the desert for 40 days and 39 nights and on the 40th night he dug a well and built a snowcone stand. Traveller's come every night to the well and drink their fill from the well, yet every morning when Jesus comes to collect the ice he finds the well full of water because it's a fucking desert and hot af. But back at the truck he has a freezer and an ice shaver because snowcones sell like pancakes, bitches.
Anonymous No.16836808 [Report]
Nigger, stop making psued threads like this and fuck off. Think for yourself for once in your life. Stop being a fucking braindead follower asking about rules and what rule you should fucking obey.

Once you understand number theory and god help you, some fucking real analysis, you can just make shit up because you understand the foundations of numbers and mathematics intuitively. Mathematics becomes art and less of a science at that point. You can just EXPRESS whatever the fuck you want, because you understand how to THINK math instead of just being a fucking calculator.
Anonymous No.16836834 [Report] >>16836837 >>16836888
>>16836768
My thoughts are that we could define an absorptive inverse. In this case, I use the term indeterminate to refer to it, but a less ambiguous term might be "semivalued"
Effectively, I see it still as acting as an absorptive notion. eg:
[math]1 \div 0 = semivalue[/math]
[math]1 + semivalue = semivalue[/math]
This can hold trivially for any operation, any function, unless defined otherwise. Not sure where and when you'd want to do that, maybe for boolean operations so we don't have to change logics? That would also imply you can assign identities to semivalues, even if they're absorptive.
[math]1 \div 0 \neq 2 \div 0[/math]

My question is, why didn't we just do this?
"Undefined" makes sense for this example:
[math]24.1.2 [[/math]
But re-using defined/undefined as a fence against some of the weirder behaviors of algebra doesn't just seem sub-optimal, but inherently wrong. Division by zero is left undefined for completely different reasons than the above. The inability to formulate and represent that difference in a concrete, unambiguous manner would mean a strengthening of the formal system.
Anonymous No.16836837 [Report]
>>16836834
>The inability to formulate
ability*
Anonymous No.16836888 [Report] >>16836909
>>16836834
>why not cover everything with partially semi-clopen sets?
>we can average across these semivalues to achieve attraction
Anonymous No.16836897 [Report] >>16836909 >>16836912 >>16837099 >>16837106 >>16839084
>>16836585 (OP)
x/0 = x
simple as
Anonymous No.16836909 [Report] >>16836912
>>16836897
I was always fond of this definition.

>>16836888
Wait until I post my antivalue thread.
Anonymous No.16836912 [Report]
>>16836897
I'm in, you crazy bastard.
>>16836909
Literally can not hold my pee. C u l8r, m8.
Anonymous No.16837010 [Report]
>>16836673
>Because it was explicitly defined that way.
No it was not. It's a natural consequence of the way division is defined.
If you split 6 apples between 3 boxes, each box gets 2.
If you split 6 apples between zero boxes, how many apples does each box get? The question is nonsense because there aren't any fucking boxes.
Anonymous No.16837046 [Report] >>16837090
>>16836585 (OP)
Because division is defined as multiplication of the inverse and 0 has none?
Anonymous No.16837081 [Report]
>>16836804
That's actually a really helpful expanation, thanks
Anonymous No.16837090 [Report] >>16837517
>>16837046
Uh, Boss. The apple warehouse is full of empty boxes.
Can I just put down 0 and go home? I really do not want to count all these empty boxes.
Anonymous No.16837099 [Report]
>>16836897
Maybe on planet retard
Anonymous No.16837101 [Report] >>16837533
>>16836585 (OP)
It's just terminology when using limits or not. If taking a limit results in dividing by something that's zero at its limit then it's indeterminate at that point. But if you're just dividing by regular zero without considering limits then it's undefined.

Dividing by zero is undefined because you can't divide something into zero parts. Like if you cut an apple in half you're dividing it by two. But if you try to cut an apple into zero parts that doesn't make any sense, so it's undefined. Not cutting the apple at all is the same as dividing it by one.
Anonymous No.16837106 [Report] >>16837107 >>16837615
>>16836897
x/1 is already x though. If x/0 was also x then that would mean 1 = 0
Anonymous No.16837107 [Report] >>16837306
>>16837106
That's not true. 0/2 = 0/1 but 2 isn't equal to 1
Anonymous No.16837203 [Report]
i think because it can go infinitely many times and never amounting to anything. well that was the answer i gave my math teacher and she liked it
Anonymous No.16837306 [Report] >>16837310
>>16837107
Thats not true, it violates the monadic function postulate
Anonymous No.16837310 [Report]
>>16837306
I violated your mother
Anonymous No.16837370 [Report]
>>16836585 (OP)
because mathematicians are fucking stupid

2*0 = 2-2

(2-2)/0 = 2
Anonymous No.16837382 [Report] >>16837945
>>16836585 (OP)
purely historical or is there a reason:
>this expression is valid, but there is nothing that satisfies it

It DOES work!!!

You can rephrase the whole set theory with a new term e_x(P) for every formula P and every letter x, and adding (for any letter y, any term t and formulas Q,E) the axioms "Q[x:= t] => Q[x:= e_y(Q)]" and "(forall y (Q <=> R)) = > e_y(Q) = e_y(R) " obtaining what is called the "epsilon calculus" of David Hilbert and Wilhelm Ackermann. The intuitive meanijng of e_x(P) is "a certain object satisfying P(x) whenever it is possible".
If the whole universe of the discourse is well ordered (for instance a model of ZF satisfying Gödel constructibility axiom) then e_x(P) has a simpler interpretation: it is the smallest (for the well ordering) object satisfying P(x) if there is one, and otherwise e_x(P) is the smallest object in the universe.
The epsilon calculus is conservative over classial first order calculus (see the "extended first epsilon theorem" on the web) and for ZFC (set theory with choice) there is a more direct proof (cf V.N.Grishin: "the theory of Zermelo-Frankel sets with Hilbert epsilon terms").

Any concept in math can be made an abbreviation of an epsilon calculus expression (a formula for a property, an epsilon term for an object).
"a/b" is thus an abbreviation of "e_x (a = b * x)" fo ANY terms a,b (yet for having proper theorems you'd need to check that a and b are both numbers and that b =/= 0 of course ;-) ).
Th
Anonymous No.16837517 [Report] >>16837576
>>16837090
0/a = 0 yeah
Anonymous No.16837533 [Report] >>16837537
>>16837101
>Dividing by zero is undefined because you can't divide something into zero parts
Sure you can, you destroy the object. Now there are no parts.
Anonymous No.16837537 [Report]
>>16837533
Uhhhh but matter cannot be destroyed thoughbeit
Anonymous No.16837576 [Report]
>>16837517
Thanks, Boss. See ya next shift.
Anonymous No.16837615 [Report]
>>16837106
no because 1 is a defined amount while 0 is an abstract denoting the lack of any amount, x/0 = x because you're not dividing x with anything, in essence not doing any arithmetic on it at all
Anonymous No.16837638 [Report] >>16837641
>>16836585 (OP)
just make anything divided by 0 equal ꝏ
>b-but what about function 1/x going up and do...
+ꝏ = -ꝏ. there. one comes after the another. solved
Anonymous No.16837641 [Report] >>16837660 >>16837672 >>16837892
>>16837638
what about ꝏ divided by 0?
Anonymous No.16837660 [Report]
>>16837641
haven't checked that. perhaps ꝏ should change a sign
Anonymous No.16837672 [Report]
>>16837641
Infinity squared. Duh.
Anonymous No.16837763 [Report]
¿what is the remainder when you divide by zero?
Anonymous No.16837790 [Report] >>16838976
>>16836585 (OP)
because division is defined as the inverse operation to multiplication, such that a number times its inverse equals 1, and every number must have exactly one inverse. But because x*0=0 for any x, and for no x does x*0=1, there's no inverse to 0.
Anonymous No.16837892 [Report]
>>16837641
ꝏ/0=ꝏ and 0/ꝏ=0
Anonymous No.16837945 [Report]
>>16837382
that feels like using a nuke to slice bread
Anonymous No.16838161 [Report]
>>16836590
Can existence exist without math?
Anonymous No.16838841 [Report]
>>16836590
No it doesn't break, is just not a number.
Anonymous No.16838925 [Report]
>>16836585 (OP)
They keep asking this question, because they've been told "you can't device by zero". They want to riot and ask "why".

When I'll have a child, I'll just ignore that problem. And if he asks me, what if we divide by zero, I'll just move my eyes away.
- What if we divide by zero?
- Huh? The next task is...
Anonymous No.16838976 [Report] >>16839508
>>16837790
my problem is that in this case, we undefine the expression rather than just saying "nothing exists to satisfy it". we treat these as equal, having no way to distinguish between unstructured collections of characters, and a structured collection of characters that just so happens to have interesting properties.
Anonymous No.16839019 [Report]
Midwit here, why isn't it just zero?
Anonymous No.16839027 [Report] >>16839043
>>16836585 (OP)
algebraic reason
you can show: If 0 has an inverse in a ring, then you're dealing with the 0 ring
Anonymous No.16839043 [Report]
>>16839027
>this is rather degenerate
Then how come it hasn't been normalized yet?
Anonymous No.16839055 [Report] >>16839703
>>16836780
If you had 0 people and tasked them with drinking a total of 1L of water each of them would have to drink an infinite amount of water to get to 1L.
Anonymous No.16839066 [Report] >>16839071 >>16839163
>>16836780
>if you divide 1L of water amongst 0 people each of them gets 0 L since nobody got any water
"I divided it equally between 0 people and each person got X liters of water" is vacuously true, but basic logic is above your kindergarten-tier skills, just like the rules of arithmetic.
Anonymous No.16839071 [Report]
>>16839066
is vacuously true for any X*
Anonymous No.16839084 [Report] >>16839758
>>16836897
>x/0 = x
Das rite. If you divide something 0 times, you're not actually dividing it.
Anonymous No.16839163 [Report]
>>16839066
mathematical logic is weaker than naive reason, it can't even deal with ambiguity.
Anonymous No.16839508 [Report] >>16839620
>>16838976
the expression is undefined because what the expression x/0 really means is x * 0^(-1), and 0^(-1) is a non-existent mathematical object. It's like saying "Let y be a whole number whose square is 11" and then write all sorts of funny formulas with it.
Anonymous No.16839620 [Report]
>>16839508
Right, but I'm saying we shouldn't use undefined in this case
Anonymous No.16839703 [Report]
>>16839055
that doesn't make sense. They would have to drink over 2L (and over 3, 4, ...) of water to get to 1L?
Anonymous No.16839741 [Report] >>16839862
>>16836585 (OP)
> why is division by zero undefined rather than indeterminate? is it purely historical or is there a reason:

Indeterminate quantities (0/0, inf/inf, inf-inf, etc.) sometimes have exact and convergent limits. This is never the case with x/0 where x =\= 0. Any possible variation on x/0 will have two different left and right limits (-inf or inf).
Anonymous No.16839758 [Report]
>>16839084
What if you divide something HALF times?
Anonymous No.16839862 [Report]
>>16839741
Makes sense anon, thanks.