I saw this Reddit post today saying "My son's third-grade teacher taught my son that 1 divided by 0 is 0. I wrote her an email to tell her that it is not 0. ...
Anything /0 is considered impossible as an agreement. There’s no actual math involved in that answer. In reality you can divide by 0, but the answer has no natural number.
How many times can you add 0 before you get 1?
The answer actually is the drunk(😅) 8 or ‘infinite’, but our minds can’t grasp the very existence of infinite, so we just went with ‘impossible’.
There are ways to circumvent that added concept of some calculators when dividing by 0 anyway and it will show you “Infinite” if it is able to. I remember you could do this in C+ even, but not 100% sure anymore how. I think it was with dividing by an ever decreasing number-variable. When it reaches 0 just before the calculation, C+ didn’t default to an error, but just said ‘Infinite’. But like I said, not 100% sure anymore if that was the actual way.
If your counter against that is that 0 will never become 1 no matter how many you add, then that just proves ‘infinite’ correct. If it ever could, it wouldn’t be infinite…
Sooo, this guy is smart, but also wrong in his calculation here. 😅
Edit: Anyway, voting me down doesn’t change the inconvenient truth above. 😅
the limit of y in 1/x=y as x approaches 0 from negative one is negative infinity. the limit as x approaches 0 from positive one is positive infinity. 1/0 is simultaneously both positive and negative infinity and is paradoxical.
One could argue that negative and possitive infinity, unlike natural numbers, boils down to the same thing, though. Just like 0, infinity technically has no + or -.
Don’t think of infinity as a value. It’s more of a concept to explain numerical behavior. What you described would be like running north at 5 mph south. The limit diverge do it does not exist.
But it is a value. Just one we tend to avoid by claiming it doesn’t exist or is impossible…
Our minds just have a hard time imagining it, but that doesn’t mean it doesn’t exist.
Our minds? Infinity isn’t something we don’t understand - we invented the concept of infinity. The mathematics community agreed on its definition, which includes the fact that infinity is not a real number, it literally does not exist. Show me infinity, I’ll give you infinity+1.
You deciding that infinity means something else is not a math problem but a language problem, so if being right about this is that important to you, start a petition or something
No, it’s not a value. It’s defined as not being a value. No after how much you bend and break maths, infinity will never be a value. Why do you keep telling people wrong things?
It is explicitly not a value. The reason you cannot perform arithmetic on infinity is because it has no value. It has cardinality but that is not unique. The set of all integers is infinite as is the set of all real numbers but they have different cardinality as integers are countably infinite whereas real numbers are not countable infinite.
I’d only break argumentative math, not actual calculatable math…
Unlike many always say, math has too many agreements and ‘definitions’ and things we added to be universal. On a universal level infinite solves the +/- by the fact it’s infinite…
It breaks calculus, the math that made your phone and has a billion other uses. Directionality of infinities is critical. In calculus, infinity refers only to the magnitude of the resulting vector. Because I suspect you don’t know, integers are a 1-dimensional vector.
No but some of the values/specs were calculated by summing an infinite number of infinitely small values. Take a calculus class brother, it’s a cool subject if you’re interested in infinity
I kinda already did many, though. Do you honestly think I argue math from my own imagination? Not sure I can do that while remaining logical ánd finding exactly the same info online if I look it up, cause that would be kinda amazing.
Okay, so what? Breaking useful things is bad, no matter what group they belong to. What is positive about no longer being able to use L’Hopital’s rule?
Quora has many dubious answers. I wouldn’t use it for any point of argument.
Infinity is not a number. It’s a concept. You’ll find yourself in many paradoxes if you start treating infinity as a number (you can easily prove that 1 = 2 for example).
By your argument, is 1/|x| negative infinity when x is 0? The expression is strictly positive, so it doesn’t make sense to assign it a negative value. But your version of infinity would make it both positive and negative.
Another one: try to plot y = (x^2 - 1) * 1/(x - 1). What happens to y when x approaches 1? If you look at a plot, you’ll see that y actually approaches 2. What would happen if we treat 1/(1-1) as your version of infinity? Should we consider that y could also approach -2, even if it doesn’t make any sense in this context?
Curious I found something that proofs my whole point exactly to the letter though… I must be exactly the same kind of wrong as that other person that actually drew you the circle with it as proof…
We do have a concept of limits in math. That doesn’t mean we ignore it. It is just more correct not to divide by zero as the limits from either side do not converge. Or would you allow -inf as an answer aswell? That is the answer if we approach the limit from the other side.
It is not only convenience but rigor that dictates dividing by 0 to be an erroneus assumption.
It was drilled into my head in school that it’s not a proper limit unless it includes the text “lim A->B”. So using infinity at all, without specifying that you’re taking the limit, would be incorrect. This makes sense as infinity isn’t a real number that you can actually be “equal to”, just a concept you can approach, so you need to specify that by taking the limit, you’re only approaching infinity. I guess the guy you’re replying to needs to hear this more than you though.
One positive infinity doesn’t even necessarily equal another positive infinity, as two expressions might not approach infinity at the same rate. Note the word “approach”. That’s the only way you’re allowed to use infinity/-infinity, by approaching it. It’s not a real number, it doesn’t actually exist. Second, in most contexts (calculus) it strictly refers to magnitude (ie, it can have directionality applied to it). Take a calculus class if you want to learn more.
If your counter against that is that 0 will never become 1 no matter how many you add, then that just proves ‘infinite’ correct. If it ever could, it wouldn’t be infinite…
You’re confusing infinity for unreal numbers. Infinity and negative infinity are not real numbers, but not all unreal numbers are infinity or negative infinity.
If you’re strictly adding zeros, then adding infinite zeros nets you zero. If adding zero once didn’t change the result, then adding it infinite times won’t either. If you need to add enough zeros to get to 1, that number doesn’t exist - but that doesn’t mean that it’s infinity, it means that there’s no solution. Infinity is a placeholder for “larger a real number than you can imagine”, but when you multiply that by zero, the magnitude of infinity is a moot point because you have zero infinities.
In calculus if you’re curious, you’re usually not strictly adding zero itself like above but instead adding values that approach zero. In that case, 0*infinity really “a very small number times a really big number”, and that is called an “indeterminate form”. In that case you may try rearranging it to solve
You say it yourself. If you keep adding infinite zeros you will never get 1, hence the ‘divided by 0’ part.
Also, 0 is technically not a number either, it’s the concept of the absence of one. You can’t count 0 things. That doesn’t mean we don’t use it, though. It’s just less hard to imagine and closer to our basic calculations than infinity is.
Division is defined as the inverse of multiplication. The answer to one divided by zero is the same as asking which number you would multiply by zero in order to get one. No number has that property, not even infinity. So the answer is undefined.
One divided by ‘epsilon’, where epsilon represents a very tiny number, approaches infinity for ever tinier epsilons, so in some maths contexts infinity makes sense. But in general it’s a meaningless question, and so can only have a meaningless answer.
Anything /0 is considered impossible as an agreement. There’s no actual math involved in that answer. In reality you can divide by 0, but the answer has no natural number.
How many times can you add 0 before you get 1? The answer actually is the drunk(😅) 8 or ‘infinite’, but our minds can’t grasp the very existence of infinite, so we just went with ‘impossible’.
There are ways to circumvent that added concept of some calculators when dividing by 0 anyway and it will show you “Infinite” if it is able to. I remember you could do this in C+ even, but not 100% sure anymore how. I think it was with dividing by an ever decreasing number-variable. When it reaches 0 just before the calculation, C+ didn’t default to an error, but just said ‘Infinite’. But like I said, not 100% sure anymore if that was the actual way.
If your counter against that is that 0 will never become 1 no matter how many you add, then that just proves ‘infinite’ correct. If it ever could, it wouldn’t be infinite…
Sooo, this guy is smart, but also wrong in his calculation here. 😅
Edit: Anyway, voting me down doesn’t change the inconvenient truth above. 😅
the limit of y in 1/x=y as x approaches 0 from negative one is negative infinity. the limit as x approaches 0 from positive one is positive infinity. 1/0 is simultaneously both positive and negative infinity and is paradoxical.
One could argue that negative and possitive infinity, unlike natural numbers, boils down to the same thing, though. Just like 0, infinity technically has no + or -.
Don’t think of infinity as a value. It’s more of a concept to explain numerical behavior. What you described would be like running north at 5 mph south. The limit diverge do it does not exist.
But it is a value. Just one we tend to avoid by claiming it doesn’t exist or is impossible… Our minds just have a hard time imagining it, but that doesn’t mean it doesn’t exist.
Our minds? Infinity isn’t something we don’t understand - we invented the concept of infinity. The mathematics community agreed on its definition, which includes the fact that infinity is not a real number, it literally does not exist. Show me infinity, I’ll give you infinity+1.
You deciding that infinity means something else is not a math problem but a language problem, so if being right about this is that important to you, start a petition or something
So you believe the universe just ends somewhere with nothing behind it?
What’s that got to do with anything? Infinity is just shorthand for “ever-increasing number”.
Uhm… No it’s not… 🤨
No, it’s not a value. It’s defined as not being a value. No after how much you bend and break maths, infinity will never be a value. Why do you keep telling people wrong things?
It is explicitly not a value. The reason you cannot perform arithmetic on infinity is because it has no value. It has cardinality but that is not unique. The set of all integers is infinite as is the set of all real numbers but they have different cardinality as integers are countably infinite whereas real numbers are not countable infinite.
If you were to argue this, you’d suddenly break a lot of useful maths. So why would you do so?
I’d only break argumentative math, not actual calculatable math…
Unlike many always say, math has too many agreements and ‘definitions’ and things we added to be universal. On a universal level infinite solves the +/- by the fact it’s infinite…
It breaks calculus, the math that made your phone and has a billion other uses. Directionality of infinities is critical. In calculus, infinity refers only to the magnitude of the resulting vector. Because I suspect you don’t know, integers are a 1-dimensional vector.
Nothing in my phone is either infinite, nor negative.
No but some of the values/specs were calculated by summing an infinite number of infinitely small values. Take a calculus class brother, it’s a cool subject if you’re interested in infinity
I kinda already did many, though. Do you honestly think I argue math from my own imagination? Not sure I can do that while remaining logical ánd finding exactly the same info online if I look it up, cause that would be kinda amazing.
Okay, so what? Breaking useful things is bad, no matter what group they belong to. What is positive about no longer being able to use L’Hopital’s rule?
Infinite is not calculable math. If you use infinity in your calculations you will get slapped on the wrists by a math professor.
Google is your friend. I’m gonna leave this here and stop arguing about infinity to people that obviously have no understanding of it.
Quora has many dubious answers. I wouldn’t use it for any point of argument.
Infinity is not a number. It’s a concept. You’ll find yourself in many paradoxes if you start treating infinity as a number (you can easily prove that 1 = 2 for example).
By your argument, is 1/|x| negative infinity when x is 0? The expression is strictly positive, so it doesn’t make sense to assign it a negative value. But your version of infinity would make it both positive and negative.
Another one: try to plot y = (x^2 - 1) * 1/(x - 1). What happens to y when x approaches 1? If you look at a plot, you’ll see that y actually approaches 2. What would happen if we treat 1/(1-1) as your version of infinity? Should we consider that y could also approach -2, even if it doesn’t make any sense in this context?
Curious I found something that proofs my whole point exactly to the letter though… I must be exactly the same kind of wrong as that other person that actually drew you the circle with it as proof…
C’mon, now you’re just reaching.
We do have a concept of limits in math. That doesn’t mean we ignore it. It is just more correct not to divide by zero as the limits from either side do not converge. Or would you allow -inf as an answer aswell? That is the answer if we approach the limit from the other side.
It is not only convenience but rigor that dictates dividing by 0 to be an erroneus assumption.
It was drilled into my head in school that it’s not a proper limit unless it includes the text “lim A->B”. So using infinity at all, without specifying that you’re taking the limit, would be incorrect. This makes sense as infinity isn’t a real number that you can actually be “equal to”, just a concept you can approach, so you need to specify that by taking the limit, you’re only approaching infinity. I guess the guy you’re replying to needs to hear this more than you though.
Infinite, just like 0, actually has no - or +. So yes and no. For all intents and purposes -inf == inf.
This is completely wrong, please don’t listen to this person.
I suggest you Google “Projectively Extended Real Numbers”.
You mean this one?
Now tell me, do we usually work with the projectively extended real numbers?
One positive infinity doesn’t even necessarily equal another positive infinity, as two expressions might not approach infinity at the same rate. Note the word “approach”. That’s the only way you’re allowed to use infinity/-infinity, by approaching it. It’s not a real number, it doesn’t actually exist. Second, in most contexts (calculus) it strictly refers to magnitude (ie, it can have directionality applied to it). Take a calculus class if you want to learn more.
You’re confusing infinity for unreal numbers. Infinity and negative infinity are not real numbers, but not all unreal numbers are infinity or negative infinity.
If you’re strictly adding zeros, then adding infinite zeros nets you zero. If adding zero once didn’t change the result, then adding it infinite times won’t either. If you need to add enough zeros to get to 1, that number doesn’t exist - but that doesn’t mean that it’s infinity, it means that there’s no solution. Infinity is a placeholder for “larger a real number than you can imagine”, but when you multiply that by zero, the magnitude of infinity is a moot point because you have zero infinities.
In calculus if you’re curious, you’re usually not strictly adding zero itself like above but instead adding values that approach zero. In that case, 0*infinity really “a very small number times a really big number”, and that is called an “indeterminate form”. In that case you may try rearranging it to solve
You say it yourself. If you keep adding infinite zeros you will never get 1, hence the ‘divided by 0’ part.
Also, 0 is technically not a number either, it’s the concept of the absence of one. You can’t count 0 things. That doesn’t mean we don’t use it, though. It’s just less hard to imagine and closer to our basic calculations than infinity is.
Zero is a real number, but not a natural number. I’m not going to explain the difference because, dude, this is junior high math
Indeed, and infinite isn’t… It’s like comparing Newton and Einstein on a regular earth scale.
Right, infinity is late high-school, early university math.
Also not really relevant but you know that elementary mechanics approximates the theory of relatively at regular earth scale?
I was always taught it was infinity as opposed to impossible.
Division is defined as the inverse of multiplication. The answer to one divided by zero is the same as asking which number you would multiply by zero in order to get one. No number has that property, not even infinity. So the answer is undefined.
One divided by ‘epsilon’, where epsilon represents a very tiny number, approaches infinity for ever tinier epsilons, so in some maths contexts infinity makes sense. But in general it’s a meaningless question, and so can only have a meaningless answer.
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