Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

vac33 Group TitleBest ResponseYou've already chosen the best response.0
Because the answer would be undefined.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
What do you mean?
 one year ago

sthop456 Group TitleBest ResponseYou've already chosen the best response.1
because you can then create a bunch of false proofs such as 2=1. Notice the last step of the following false proof is actually just division by zero: a = x [true for some a's and x's] a+a = a+x [add a to both sides] 2a = a+x [a+a = 2a] 2a2x = a+x2x [subtract 2x from both sides] 2(ax) = a+x2x [2a2x = 2(ax)] 2(ax) = ax [x2x = x] 2 = 1 [divide both sides by ax]
 one year ago

vac33 Group TitleBest ResponseYou've already chosen the best response.0
Because when you get a smaller and smaller number in the denominator the number gets larger and larger (assuming it is positive) for example 1/0.00001 is much larger than one. If its 1/0 it would be infinitely large following the same trend.
 one year ago

zepp Group TitleBest ResponseYou've already chosen the best response.0
Let c (result) be \(\LARGE \frac{a}{b}\), if b was 0, then \(\large cb=a\), we need to find a number \(a\) that could be the answer to \(c*(0)\), and for all \(c\), a would always be 0. In this case, we leave this undefined.
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
dw:1353147793508:dw
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
@sirm3d neither
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
@skullpatrol so there is no correct answer. any correct answer will be contradicted by the same examples above.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
In abstract algebra, 1 is the multiplicative identity. That means that you can multiply any element by 1 and you get the number back. 4*1 = 4. 876*1=876 etc. It's the unique element that does that. You also want to have 'inverse elements'. Those are numbers that when you multiple them together, you get the identity. For example, the inverse element of 5 is 1/5, because 5 * 1/5 = 1, the identity. In multiplication, when you 'divide' by something, you are actually multiplying by the inverse element of the thing, with respect to multiplication. So when you say 4 / 5 you are actually saying 4 * 1/5. The question is, does 0 have a multiplicative inverse? What that's asking is, is there a number x such that 0 * x = 1? There can't be, because, well, from some other places, we sort of want 0 to be the element such that when you multiply anything by 0, then you get 0. So 0 has no inverse. If it did, then lots of the things from abstract algebra, which lay the foundations for arithmetic, would be violated and no longer work properly.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
(above, where I said 4 * 1/5, what I mean is that you're actually multiplying 4 by the number defined as being 1/5. So in a sense there's actually no division. There's just multiplying, by the correct number)
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
So when you say you want to divide by zero, what you mean is that you want to multiply by the number that is the "multiplicative inverse" of 0. And the multiplicative inverse of zero is the number x such that 0 * x = 1, and x * 0 = 1. And it can be thought that if such a number exists, then it would wreck everything.
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
dw:1353148249632:dw if n is the correct answer, what is n then? it would be more sensible to agree that there is no solution than argue that one answer is "more correct" than the other
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
How about 0*(1/0) = 1 @scarydoor ?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
well, the 'symbols' like 1/5 and 1/0 still need to be translated back into decimal numbers of some kind. We can represent 1/5 in decimals. What value would 1/0 take? The only two possibilities are infinity and +infinity, which aren't numbers.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Also, suppose you decide on some decimal value for 1/0 to take, called x (just some number). Then 1/0 = x. Then 1 = x * 0 = 0. So you have that 1 = 0, which means you're going to have some problems.
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
if 1/0 is a number, then \[\large 1=0\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 0 }=\frac{ 0\times5 }{ 0 \times 4 }=\frac{ 0 }{ 0 }\left( \frac{ 5 }{ 4 } \right)=\frac{ 5 }{ 4 }\] so we must agree that \[1=\frac{ 5 }{ 4 }= \text{any other number}\]
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Even if you had 1/0 = infinity, then you'd have 1 = infinity * 0. There are areas of maths where you have accepted rules to do arithmetic on the symbol infinity, and those rules say that infinity * 0 = 0. So you'd still have 1 = 0. But also, I'm not so sure you'd actually still be able to use the algebraic manipulations I used there, since if you have infinity in the system, then it's no longer really a structure of numbers. It's got some symbols in there too...
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
If 1/0 = x. Then 1 = x * 0 , but how did you algebraically derive 1 = x*0 from 1/0 =x @scarydoor?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Well, we said 1/0 is the multiplicative identify of 0. That means (the definition of multiplicative identity) that 0 * 1/0 = 1. So 1/0 = x. (now multiply each side by 0, to get...) 0 * 1/0 = 0 * x (then 0 * 1/0 = 1, so...) 1 = 0 * x. (I wrote the right hand side the other way around, but, don't worry about that... )
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
@hartnn share your thoughts. =)
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Also, this might seem weird and unconnected to normal arithmetic that you do. But this is really minimalist algebra, and was really just invented to justify the way that we think arithmetic should work (i.e., we want it to be "sensible"). These are really conservative conventions. Just abstract sounding.
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
@skullpatrol what about \[\large \frac{ 5 }{ 0 }\] is it five times as many as \[\large \frac{1}{0}\]
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.0
logically speaking, dividing something with a number 'n' means making 'n' equal parts of that 'something. dividing by 0 means you are not making any parts...so such operation is not defined
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
\[0\left( \frac{ 5 }{ 0 } \right)=\frac{ 0 }{ 1 }\left( \frac{ 5 }{ 0 } \right)=\frac{ 0 }{ 0 }=1\] because \[0\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 1 }\left( \frac{ 1 }{ 0 } \right)=\frac{ 0 }{ 0 }=1\] since this number must obey the multiplication rule for fractions.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But, you have multiplied both sided of an equation by 0. You have used 0 as a multiplier in transforming an equation, which says the final equation will be satisfied by any number no matter what the equation is. @scarydoor
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Also, try to divide 1 by 0. Divide it by increasingly smaller numbers. 1/(1/2) = 2. 1/(1/3) = 3. 1/(1/4)=4. In general, divide 1 by 1/n, where n is a natural number. 1/n gets ever closer to 0 as n gets increasingly larger. So 1/(1/n) = n. And as n goes to infinity (which means you get closer to the "true" value of 1/0) then 1/(1/n) = infinity. So, eventually you would guess that 1/0 might need to be infinity.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Oh yeah! Good point skullpatrol. Haha... Well, maybe that part of the explanation why it doesn't work needs some improvement. The other peoples' explanations might be better to look at then.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
(also, above, where I was dividing by natural numbers, you could divide by n, and then the limit comes to infinity. So there are two implied values for 1/0, at least for that approach...)
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
IF you are right that it is possible to divide by zero, that this division by zero results in some quotient and remainder, can you give an answer that is unassailable by any sound argument? @skullpatrol
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
people have struggled with the idea of 0 and infinity for thousands of years. Lots of very smart people didn't know what to do with the complications. There are two good books about it. I read one (the one where reviewers say there is less maths, whichever that is...) and found it to be a very entertaining read on the topic: http://www.amazon.com/ZeroBiographyDangerousCharlesSeife/dp/0140296476/ref=sr_1_3?s=books&ie=UTF8&qid=1353150007&sr=13&keywords=zero http://www.amazon.com/TheNothingthatIsNatural/dp/0195142373/ref=pd_vtp_b_2
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
You might be able to find one of them at a library. They will give you lots more intuition about the development of the idea of 0 (and infinity).
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
All I'm saying is a lot of Professors give the argument: If a/0=c, then a=0*c. But as we have shown this argument is flawed by the fact that you are using 0 as a multiplier in transforming a/0=c into a=0*c.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
hmn. actually.... coming to think about it, we can multiply each side by zero, right? The reason is that it "should" make both sides equal to zero. (and in fact you can multiply each side by the same number, for any number, and the equality will hold) So actually I'm going back on my reneg, and say that it was fine to multiply both sides by zero.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
The problem is that we have a number (1/0) which we defined so that 0 * 1/0 = 1.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Can you explain why it shouldn't have been okay to multiply both sides by 0? Or why you think that shouldn't have been allowed? Because if you can be convinced that it was allowed, then that would confirm that we shouldn't be allowed to divide by zero, right?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Also,they are implying that 0*(a/0) = 0*(1/0)*a and then 0*(1/0) = 1 but we know that 0 has no reciprocal because 0 times any number is 0 not 1.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
I don't understand what you're saying.
 one year ago

sirm3d Group TitleBest ResponseYou've already chosen the best response.2
the trouble with accepting 1/0 as a number is determining the value of a * (1/0)
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
You have used 0 as a multiplier in transforming an equation, which says the final equation will be satisfied by any number no matter what the equation is. @scarydoor
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
if (1/0) = x, and x is the multiplicative inverse of 0, then... 0 * (1/0) = 0 * x (multiply both sides by 0. (if two numbers are equal, then to multiply them by the same number, they should still be equal) 1 = 0. (since 0 * 1/0 = 1 (left hand side) and 0 * any number = 0 (right hand side) 1=0 is absurd. so the assumption that (1/0) exists and is a real number, must have been wrong. (proof by contradiction).
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
by the same assumptions I made in the first line, you could say that... 1/0 = x (then multiply both sides by a to get...) a * 1/0 = a * x (post multiply both sides by 0...) a * (1/0 * 0) = (a * x) * 0 a * 1 = 0 a = 0. This is true for any number a..
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Any equality will be satisfied by any real number if you multiply both sides by 0. for example x=5 is only satisfied by 5 but 0*x=0*5 or 0*x=0 is now satisfied by any real number so it is not equivalent to the original equation x=5.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
But to make that claim, you have assumed you can divide by 0! That's the bad link. you said that if you can say 0*x = 0*5, then x must be equal to 5. But how did you get rid of the 0? You must have tried to divide by 0. That's basically what I'm saying in the argument above.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Are you convinced?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
I'm saying starting with the original equation x=5 and asking for what values is it satisfied for? The answer is 5, because when we substitute 5 into the original equation we get a true statement 5=5.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
which original equation? I'm not sure where you think the problem is.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Take any equation as your original equation try: 8z=40 the solution set to this equation is {5}.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
That's right.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Now transform that original equation by multiplying both sides by 0.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
I think you're saying that if I now say that 0 * 8z = 0 * 40, then the solution for z is any number. And you think that's a problem because before we said that z = 5.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
The problem is in direction of implication. I can say that if 8z = 40, then 0 * 8z = 0 * 40. But I can't say that if 0 * 8z = 0 * 40 then 8z = 40. Because I'm saying that 0 = 0 means that 8z = 40.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Yes, that is correct. Zero is not allowed as a multiplier in transforming equations.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
It's allowed as a transformation, but the implication is only one way. If it's not zero then I can get back again. but with zero I can't.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
So, before I said that 1/0 = x is an equality. Then I multiply both sides by 0, I'm going in the correct direction for the implication... 1/0 * 0 = x * 0. This equality still holds. Now I use that 1/0 is the identiy of 0, and that x * 0 = 0... 1 = 0.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
What you are trying to do is go in the other direction. But I don't need to go in the other direction, so I don't care that I can't.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
think about this.... 6 = 3 * 2. That's correct. Now multiply both sides by 0. We get that 0 = 0. Can we conclude, from 0 = 0 that 6 = 3 * 2? We can't. Actually this all comes back to the fact that we can't divide by zero, and that's because 0 is the annihilator. If we could divide by zero, then we could go in the backwards direction too.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Does that make sense?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
If you have x = y, then a * x = a * y for any number a. Now, so long as a is not zero, then 1/a * a * x = 1/a * a * y. Which means that 1 * x = 1 * y. x = y. So you can go both ways. Notice that the only reason you can't go backwards again if a is equal to zero is that you can't divide 1 by zero. (where a = 0, 1/a = 1/0).
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
I agree :)
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
haha, good.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
algebra is fun.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But the definition of equivalent equations is equations that have the same solution set and multiplying both sides by 0 , because 0 is the annihilator. Annihilates all the information with any equation, so it is not allowed.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
it's not allowed if you want to preserve all the information. But I didn't want to, so it didn't matter. I only wanted to produce a new true equation from an old true equation. The new true equation was all I cared about.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
you're completely right though, that if you want to solve for some variable or something, but doing equality preserving arithmetic on them, then you don't want to multiply by zero. But in this case, notice that I didn't need to preserve everything.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Also, in most cases you wouldn't want to multiply by zero, because it destroys all information. BUT here, we said that there are two things with zero: it makes everything zero, and that 0 * 1/0 = 1. This second one isn't normally the case because we actually can't divide by zero. And so it's only in this "what if we could" scenario that we get some benefit out of multiplying both sides by zero. So I guess the reason that you feel strongly against multiplying by zero, is that in every other case, it's not a good thing to do. .... and the reason for that is because we can't divide by zero.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
for example, if you have a x = b, and you want to find x. You would multiply by 1/a, to get x. You could also multiply by any other number, except zero, and still have hope of finding x. If you multiplied by 0, then you have destroyed all information (unless I could make the zeroes disappear by divide through by them...)
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
(.... like I assumed you could. and then ended up with 1=0)
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Hi @helder_edwin
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
I don't believe there's much more to say.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
I read everything u people wrote.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
I believe the argument: If a/0=c, then a=0*c. Is flawed. @helder_edwin
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
first of all \(1\neq0\) because otherwise we would have \[ \large a=1\cdot a=0\cdot a=0 \] for every real \(a\). so all the real numbers would be zero and that makes no sense and would render calculus useless.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Agreed.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
in order to define division we gotta have multiplicative inverses (i don't the word in english for "recíprocos") i.e. \[ \large \frac{a}{b}=a\cdot b^{1} \]
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
provided b is not zero. that is, zero doesn't have multiplicative inverse.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
suppose 0 actually has a multiplicative inverse, \(0^{1}\). then \[ \large \frac{0}{0}=0\cdot0^{1}=1 \] but also \(0\cdot0^{1}=0\). so we should have 0=1.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
therefore, zero does NOT have multiplicative inverse, so one cannot define division by zero.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Therein lies the problem. I'm saying you can not write any number divided by 0 first. Because multiplication defines division.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
regarding the argument (proposition) \[ \large \frac{a}{0}=c\qquad\Rightarrow\qquad a=c\cdot0 \]
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Yes, how can you algebraically go from a/0=c ?> to a=0*c
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
@skullpatrol it sounds like you're saying "I don't believe it's true that we can't divide by zero" so then the argument is "okay suppose we can divide by zero, then..." and then you're saying "but how can you do that? You can't divide by zero..."
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
maybe you professor was trying to make the point like this: "suppose we could write for \(a\neq0\) \[ \large \frac{a}{0}=c \] then we could infer from this that \[ \large a=c\cdot0=0 \] which contradicts the assumption"
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
How do you "infer"? I want to know the algebraic steps used, Sir.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
"now. even if we let \(a=0\) then we would have \[ \large \frac{0}{0}=c\Rightarrow 0=c\cdot0 \] and this last equation is satisfied by any number c. so we end up having \[ \large \frac{0}{0}=0=1=2=\pi=e^\pi=... \] which is absurd.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
@skullpatrol do you know how a proof by contradiction works?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
a=bc defines a/b=c.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
that's the whole point. if u r supposing somehing is true then, all other relevant rules apply. including common algebra.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So we are supposing if a/0=c, then how do you prove a=0*c.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
You are also supposing that there exists a number 1/0 such that 1/0 * 0 = 1.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
u don't.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
"u don't." why not?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
a/0= a*1/0 = c, then a * 1/0 * 0 = c * 0. Then a * 1 = c * 0 = 0. ie a= 0.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
because it's algebraic manipulation: \[ \large a\cdot0^{1}=\frac{a}{0}=c \] \[ \large a=a\cdot0^{1}\cdot0=c\cdot0 \] there u have a "proof".
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But you multiplied both sides by 0
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
And then left :(
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
if you know that x = y, is it true that x * 0 = y * 0?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
just finished a maths degree... you? I'm trying to tell you that it's okay to multiply both sides of an equation by zero. I've just taken all undergraduate courses on algebra that my university offers. I think I'm qualified to state that it's okay in this case :p.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
(the above is a reply to the question by @skullpatrol patrol "what grade are you in?") Thanks for the implication that I don't appear very intelligent, buddy. Maybe I'll stop trying to help you understand it, eh...
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
the question seems to have been deleted just as I answered.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
sorry i left. i'm in a place with the worst internet service ever.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
we (myself and @scarydoor ) are multiplying by zero because we are using a proof by con
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
*contradiction
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So it is OK to multiply both sides of an equation by 0 even though the final equation is satisfied by any real number.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
u never multiply an equation by zero, unless, as u pointed out, u want to loose the "information" the equation provides.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Thank you for confirming that Sir.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
@skullpatrol ???
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So why are we allowed to do it here? If a/0=c, then a=0*c.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
it is a proof by contradiction!!
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
you are always allowed to do it. Just usually it doesn't do you any good. We only do it here because here, we have 1/0 * 0 = 1, because we assumed we could do that, because it's a proof by contradiction. In any other situation we know that dividing by zero destroys all information, and therefore is useless to us (even though it's correct, and the equality is preserved), so we don't do it in any other place. (even though we can. but it never helps us elsewhere)
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
The reason people tell you not to is not because it breaks arithmetic rules. The reason they tell you not to is because it won't help you do anything, where we haven't temporarily altered the rules of arithmetic.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
That's why I asked you, if y=x, then does 0*y = 0*x? answer that, and then you'll see that there's nothing wrong with the proof. The only problem you find is that, normally you would find no practical value in multiplying by zero. Besides that, it doesn't break any rules to do so.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But this (1/0)*0=1 is already a contradiction of the multiplicative property of 0, that is 0 times any number is 0, not 1.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
but wasn't your theory that you can divide by zero? That's what you're assuming is true. If you can, then 1/0 * 0 = 1. That's basically the definition of what it means to be able to divide by zero. That's what we assume, and then derive that a = 0 for any number a.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
Yes, it's a contradiction to the axiom that 0 times any number is 0. So that's one problem. What we show is that another problem, ignoring that first one, is that if you take it to be true then a = 0 for any number a.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
again. that's the whole point. u started with something u SUPPOSED to be true, and infered something absurd. ergo, your initial assumption was wrong.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
If a/0=c, <u started with something u SUPPOSED to be true then a=0*c. <inferred something absurd. ergo, your initial assumption was wrong.a/0=c
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
yes. u can't divide by zero.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
the whole of the assumption is: 0 is invertible, and so for any number a, a/0 is defined. ie a/0 = c for some number c. That's the assumption that is proven false.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
And it is proven to be false by using the false assumption that 0 is invertible and using 0 as a multipier in transforming the equation.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
If a/0=c, <u started with something u SUPPOSED to be true 0*(a/0)=0*c 0*(1/0)*a=0*c 1*a=0*c then a=0*c.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
yep. read a book on abstract algebra maybe.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
How can you prove something is false using a false assumption?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
when I asked if you know how a proof by contradiction works, you said you do... You should go and read about it. I might not be in a high enough grade for you to take me seriously, afterall.
 one year ago

helder_edwin Group TitleBest ResponseYou've already chosen the best response.0
the discussion was very interesting. i hope we were helpful.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
It just seems so obvious that 0 times any number is 0. And then to use 0*(1/0) = 1 feels completely wrong!!! In my opinion :(
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
I guess the lesson to learn here is "1/0" is not any number.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
http://en.wikipedia.org/wiki/Proof_by_contradiction
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Thank you for your patience and guidance.
 one year ago

DarkGhost Group TitleBest ResponseYou've already chosen the best response.0
I'll just leave this here http://www.khanacademy.org/math/arithmetic/numberproperties/v/whydividingbyzeroisundefined
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
for example if you have 2 apples and you are supposed to split it with 0 people, it is not possible because there is no one to split it with
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
You could say the answer to that question is nobody gets the 2 apples.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
no i mean you are required to split it to 0 people, it is not possible since you cannot split it with 0 people 2/0 = undefined
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Here: 2/0 "=" undefined you are using the "=" for "is" What I'm saying is 2/0 means nobody gets the 2 apples.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
what im saying is that you cannot just say no one gets the 2 apples if you are required to divide among 0 people
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
If there is nobody around and you are required to divide 2 among 0 people what happens to the apples?
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
it becomes undefined since its not possible to do so
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
undefined is basically we dont know what happens
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Have you fulfilled your own requirement: "if you are required to divide "
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
your question was why can you not divide by zero? so the requirement was to divide n by 0 and i just made an example by using n=2 to show you that it is undefined when you do so
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But I asked "why"?
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
i showed you why you cannot split 2 apples among 0 people since there is no one to split it with
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
so what happens to the 2 apples? we dont know so we call that undefined
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
But you said "it is undefined ***when you do so*** " so that means it ***can be done***?
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
the apples are divided we just dont know how they are divided so we use the term undefined to answer it
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
The apples are divided by 0?
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
yea when you divide the apples by 0 we will get undefined since we dont know how they are divided
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
I asked why can you NEVER divide by 0
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
like i said your question was why can you never divide by 0 so i used an example of n = 2 we'll just use n then if you have n number of items and you want to split them among 0 people then you cannot because there is no one to split n items with, and we do not know how n is divided so we get an answer called undefined
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
no matter what n is if you have no one to split it with, we will never know how n is divided
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
That is what I said: no one gets the n. That is the answer. It is not undefined because nobody gets the apples is a well defined sentence.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
i didnt say no one gets the n i said we do not know how n is divided
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
We do know how n is divided: "It is not divided" because nobody is there.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
it looks like you are making assumptions here you are saying since we dont know how n is divided you are assuming that n does not get divided instead, just because no one is there doesnt mean it does not get divided it means we dont know how it is divided so we say it is undefined
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
If no one is there we do know nothing will happen to the apples.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
again you are making assumptions how can you be so sure nothing will happen to the apples?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
How can you be so sure we don't know?
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
because it is more reasonable to say that we do not know rather that making an assumption and saying nothing happens
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
you made a conclusion by saying nothing happens whereas i say we dont know, which means we havent come to a conclusion yet, so we just give it the term undefined to say we do know what happens
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
dont know* (typo)
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So your answer is "we don't know" why we can never divide by 0.
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
no as i said before we do not know how it is divided so we say its undefined
 one year ago

jayz657 Group TitleBest ResponseYou've already chosen the best response.0
since if we ever do divide by 0 do not know what happens so you are better off just not dividing by zero
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
@skullpatrol http://www.math.utah.edu/~pa/math/0by0.html
 one year ago

sunnymony Group TitleBest ResponseYou've already chosen the best response.0
when u dived by zero so ans will be infinite.means undefind which has no meaning
 one year ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.1
You cannot divide by zero because there is no meaningful result to that operation. No element of any given set of numbers  real, imaginary or otherwise  would fulfil this equation. Infinity is not a defined number, it is merely a symbol meaning "exceeding all values". You cannot use it to perform calculations like these. ok @skullpatrol
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So each friend doesn't get any apple is the answer?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
3/6 = 1/2 each 2/6 = 1/3 each 1/6 = 1/6 each 0/6 = 0 apples each
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
"If you have 3 apples, and six friends, you can divide each apple in half that way, each friend gets half an apple."
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
Are you talking about amount of apple per friend?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
So you are counting the number of pieces each friend gets.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
6/3 =half each friend 6/2 =3rd each friend 6/1 =6th each friend
 one year ago

zostale Group TitleBest ResponseYou've already chosen the best response.0
true...its undefined. Watch the khan academy tutorial on it. Pretty logical and interesting.
 one year ago

StupidGenius Group TitleBest ResponseYou've already chosen the best response.1
i want say something, we can't divided by zero but if my problem want to divided by zero ?! we know the velocity equal to difference between density over difference between time? \[\frac{ v2v1 }{ t2t11 }\] question is what is the Instantaneous velocity? i.e find the velocity when t2 =t1?
 one year ago

StupidGenius Group TitleBest ResponseYou've already chosen the best response.1
answer is we can't put t2=t1 directly but we but it by limit at t2 tents to t1
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.0
you can't divide by zero for the same reason that it make no sense to ask how many miles per gallon i get on my bicycle \(a\div b=c\iff bc=a\) try solving \(a\div 0=b\iff 0\times c=a\) for \(c\) and non zero \(a\) for example try solving \[2\div 0=c\iff 0\times c=2\] for \(c\) and you see that you cannot
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.0
typo there, i means try solving \[a\div 0=c\iff 0\times c=a\] for \(c\)
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
hmm... shouldn't it be a=bc defines a/b=c?
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
@satellite73
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
That is a=bc > a/b=c not a/b=c> a=bc which you are combining to give a/b=c<>a=bc
 one year ago

geoffb Group TitleBest ResponseYou've already chosen the best response.0
Chuck Norris can divide by zero.
 one year ago

skullpatrol Group TitleBest ResponseYou've already chosen the best response.0
That^ is all this thread needed
 one year ago

StupidGenius Group TitleBest ResponseYou've already chosen the best response.1
you right because we con divided by zero @satellite73 but if i have to divide by value tends to zero what shall i do?
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
@StupidGenius , if you're saying you're dividing 1 / n, and taking the limit as n gets closer to zero, then that is a limit that doesn't converge to any real number. It's just a case of a limit that doesn't converge to any real number. There are lots of them. That's all covered in the area of maths called real analysis.
 one year ago

scarydoor Group TitleBest ResponseYou've already chosen the best response.6
first line, should have said: "dividing 1 by n (i.e. 1/n)"
 one year ago

StupidGenius Group TitleBest ResponseYou've already chosen the best response.1
yes i know some real analysis
 one year ago

Vogelfrei Group TitleBest ResponseYou've already chosen the best response.0
http://en.wikipedia.org/wiki/Division_by_zero
 one year ago

radar Group TitleBest ResponseYou've already chosen the best response.0
Just remember dividing by zero is done at your own risk, I choose to avoid doing such a thing.
 one year ago

StupidGenius Group TitleBest ResponseYou've already chosen the best response.1
real analysis study the series and sequence at infinite terms and it's study to seek if the valve gives infinite or number (divergence and convergence )
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.