1. Divide by Zero

 Okay. So dividing by zero makes no sense. r * 24 = 0 24/0 = 0 r = 0 0 * 24 = 0 Thus, is true? I get what I've heard for some explanations, but that's just weak. I want a technical explanation :3 EDIT: I got 24/0 = 0 like this....: If you split 24 up into 0 groups (i.e. take it away), then you are left with nothing.

2.  24 / 0 is undefined, not zero Why is this in tech forum?

3.  Yea, I've heard. That isn't an explanation.

4.  what exactly are you asking?

5.  SPECIFICALLY, why is x/0 'undefined'? Not, "Because it is undefined".

6.  The mistake you are making is assuming that splitting 24 into 0 groups is theoretically equivalent to "taking it away." Taking the 24 away would be subtraction (24 - 24 = 0). Splitting 24 into 0 groups, on the other hand, is not possible.

7.  Why not? After all, we can add 5 to itself zero times and get zero. So why wouldn't such abstractions apply here?

8.  well, it's not undefined it's infinity machines leave a divide by zero as undefined because you can't represent it Division is the ratio between 2 numbers R = a / b 12 / 4 = 3 3 = 12 / 4 the ratio between 4 & 12 is 3 put simply, 12 is 3 times larger than 4 for ever decreasing values of b, the ratio increases 12 / 4 = 3 12 / 1 = 12 12 / 0.1 = 120 12 / 0.01 = 1200 12 / 0.000000001 = 12000000000 the closer the denominator gets to zero, the larger the result if the denominator is zero, the result is infinitely large

9.  Okay, I see. Thank you. But then, it isn't undefined, it is ifinity, so why doesn't it work? Infinity is represented as 'infinity'. Any operation on it results in itself. But then, that doesn't work because r * 24 = 0 r = inf inf * 24 = inf r HAS to be 0.

10.  Should I do it? Yeah, okay. There is a way to essentially divide by zero, it's the basis of calculus. Calculus is largely about finding inventive ways to divide by zero.

11.  the closer the denominator gets to zero, the larger the result if the denominator is zero, the result is infinitely large Thats not rigor. Basically if you have y=1/x, as x tends to 0, y tends to infinty. Ironically, speaking you can actually work with that using nonstandard analysis. I have a book on abstract algebra, it touches this subject. It says something about this algebra shows thats why division by zero is not allowed, however I couldn't understand the book after about three pages. There is a way to essentially divide by zero, it's the basis of calculus. Calculus is largely about finding inventive ways to divide by zero. In calculus you never divide by zero, actually if you're forced to do that then you have to concluded it has no limit. In calculus you work with infintely small quantities, not zero.

12.  Er, not sure what you mean, Wendy... Ninja: Heh. My Uncle's taking a calculus course. Looks hella abstract }_}

13.  infinity is not a number you cannot do calculations on it infinity is a representation of a value so large (or small) you can't define it how long, in metres, is the universe? it just keeps going, and going you can fly around in a space ship all your life, placing rulers end-to-end and always need more rulers so, how long is it?

14.  Originally Posted by wendylove I have a book on abstract algebra, it touches this subject. It says something about this algebra shows thats why division by zero is not allowed, however I couldn't understand the book after about three pages. Algebra can not divide by zero, you can only do that through calculus. I assume what you are talking about is polynomials that have discrete breaks. That's not quiet the same as division by zero. Calc isn't that hard, you just have to get used to it. Ynot is correct, infinity is a concept, not a number.

15.  Originally Posted by Ynot infinity is not a number you cannot do calculations on it infinity is a representation of a value so large (or small) you can't define it how long, in metres, is the universe? it just keeps going, and going you can fly around in a space ship all your life, placing rulers end-to-end and always need more rulers so, how long is it? It is still represented as infinity. Any operation on it results in itself. What I don't understand, is this. r * 24 = 0 r = 0 This is true, because 0*x = 0 So then: r * 24 = 0 r = 24/0 r = 0 If the previous statement is true, then why is this not true?

16.  My Uncle's taking a calculus course. Looks hella abstract }_} Calculus can be done by blind monkies with broken fingers. Analysis is abstract, calculus is just doing a technique. infinity is not a number Do set theory and come back here saying that. Infinity is a number, Cantor said so. you can fly around in a space ship all your life, placing rulers end-to-end and always need more rulers so, how long is it? This means nothing, and its not rigor. Numbers are abstract, this proves nothing.

17.  Just because something can be used for mathematical functions does not make it a number. i is not a number, but i^2 is. Quaternions aren't numbers either. 0 is a weird number in math. You can take a defined equation like the one that you mentioned, move it around and make the variable be different things r * 24 = 0 : r = 0 0 / r = 24 : r = undefined r = 24 / 0 : r = infinity

18.  Originally Posted by ninja9578 Just because something can be used for mathematical functions does not make it a number. i is not a number, but i^2 is. Quaternions aren't numbers either. 0 is a weird number in math. You can take a defined equation like the one that you mentioned, move it around and make the variable be different things r * 24 = 0 : r = 0 0 / r = 24 : r = undefined r = 24 / 0 : r = infinity I didn't say it was a number... And that makes no sense. In order to find that r * 24 = 0 so then r = 0 You would have to say r = 24/0 r = 0 So. And wouldn't 0/r = 24 be false anyhow? Take nothing, split it up, and you still have nothing.

19.  Here's a quick lesson in calculus. Say you want the slope of a line at a single point in the line y = f(x). The calculus way to do that is rise over run, but in this case, run is zero because it's just a point. We need to find some way to solve for a point, so lets use the algebraic way to solve slope = rise / run f(x)' = dy / dx Chose any x, and add a little bit to it. We'll call that little bit ∆x. That ∆x is out run now, but remember we want that run to be zero, so the limit of ∆x is zero. f(x)' = lim ∆x -> 0 (dy / ∆x) Now lets change dy. We know that f(x) gives us y so f(x + ∆x) - f(x) will gives us dy. f(x)' = lim ∆x->0 (f(x + ∆x) - f(x) / ∆x) Now we need to know what the function f(x) is. For simplicity, lets use f(x) = x^2. So... f(x)' = lim ∆x->0 ((x + ∆x)^2 - x^2 / ∆x) Now lets simplify. f(x)' = lim ∆x->0(2x∆x + ∆x^2)/∆x Now we have a ∆x on the bottom and in each function in the top. This allows us to cancel them out. This is what calculus is all about, keeping that zero a variable as long as possible and finding a way to cancel it out. However you'll notice when we simplify, there still is a ∆x on the top because on of them is square: f(x)' = lim ∆x->0(2x + ∆x) But now the limit of ∆x is zero, so replace ∆x with zero. f(x)' = 2x, which is the derivative of x^2

20.  Originally Posted by A Roxxor And wouldn't 0/r = 24 be false anyhow? Take nothing, split it up, and you still have nothing. Yes, that's why that variation of that equation is undefined.

21.  Originally Posted by A Roxxor It is still represented as infinity. Any operation on it results in itself. What I don't understand, is this. r * 24 = 0 r = 0 This is true, because 0*x = 0 So then: r * 24 = 0 r = 24/0 r = 0 If the previous statement is true, then why is this not true? You fail MAJORLY at basic re-arranging of equations, and everyone else in this thread fails to varying degrees as well. r*24 = 0 divide both sides by 24: r = 0/24 r=0 If you can't understand that then I suggest you go back and redo third grade. As for the undefined/infinity discussion: A quantity x/0, x real, is undefined. To see why, look at the left and right limits of the function y=1/x as x approaches 0. The left limit will give you -infinity, and the right limit gives +infinity. Thus, the limit does not exist, and 1/0 is undefined in the reals. It's not a rigorous proof, it just demonstrates why 1/0 is not infinity. I suggest you ALL read this: http://en.wikipedia.org/wiki/Divide_by_zero

22.  Uhm, there are multiple ways to rearrange the same equation. Originally Posted by ninja9578 r * 24 = 0 : r = 0 0 / r = 24 : r = undefined r = 24 / 0 : r = infinity All are rearrangements of the same equation a * b = c can be b = c / a or a = c / b FYI: This thread is moved to the lounge as this is not a discussion on implementing division by zero.

23.  0/0 could technically be any number 'infinity' is only commonly cited because the function 1/x approaches it from the right Think about this 5*0 = 0 5 = 0/0 20* 0 = 0 20 = 0/0 135*0 = 0 135 = 0/0 According to the above statements, 5 = 20 = 135 which is why we say 0/0 is undefined, it equals any number.

24.  Originally Posted by drewmandan You fail MAJORLY at basic re-arranging of equations, and everyone else in this thread fails to varying degrees as well. r*24 = 0 divide both sides by 24: r = 0/24 r=0 If you can't understand that then I suggest you go back and redo third grade. As for the undefined/infinity discussion: A quantity x/0, x real, is undefined. To see why, look at the left and right limits of the function y=1/x as x approaches 0. The left limit will give you -infinity, and the right limit gives +infinity. Thus, the limit does not exist, and 1/0 is undefined in the reals. It's not a rigorous proof, it just demonstrates why 1/0 is not infinity. I suggest you ALL read this: http://en.wikipedia.org/wiki/Divide_by_zero ???

25.  Originally Posted by arby 0/0 could technically be any number 'infinity' is only commonly cited because the function 1/x approaches it from the right Think about this 5*0 = 0 5 = 0/0 20* 0 = 0 20 = 0/0 135*0 = 0 135 = 0/0 According to the above statements, 5 = 20 = 135 which is why we say 0/0 is undefined, it equals any number. Well yea. 'r' could be any number in r*0=0 That's the point. We know that. But, in r*x=0 (Where 'x' is any real number) then r = 0 So then, r = x/0 Which was my original question and has failed to have been answered.

Page 1 of 2 1 2 Last

Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•