• @[email protected]
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    62 years ago

    If you were to argue this, you’d suddenly break a lot of useful maths. So why would you do so?

    • Doctor xNo
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      22 years ago

      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…

      • magic_lobster_party
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        22 years ago

        Infinite is not calculable math. If you use infinity in your calculations you will get slapped on the wrists by a math professor.

          • magic_lobster_party
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            22 years ago

            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?

            • Doctor xNo
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              2 years ago

              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.

              • magic_lobster_party
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                32 years ago

                The circle is just a visualization of a concept, not a proof. The Quora answer clearly refers to this concept: https://mathworld.wolfram.com/ProjectivelyExtendedRealNumbers.html

                The page clearly states this is a non-standard number system. You cannot use it in the general case. It is a common practice for mathematicians to come up with new number systems with new rules and see where it leads to. Maybe there’s a practical use for it?

                This is the same case here. Some mathematician came up with a new number system where 1/0 is treated as a new number with special properties and see what it leads to. Any new conclusion made in this number system is probably not applicable in any standard number system.

                The article also mentions this number system: https://mathworld.wolfram.com/AffinelyExtendedRealNumbers.html

                Similarly this is a number system that has been constructed such that infinity exists as a number, but in this case negative infinity is a distinct number. 1/0 is not defined under this system as a result. This is a non-standard system as well, so shouldn’t be used unless it’s clearly intended.

                • @[email protected]
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                  22 years ago

                  This. 1/0 does not exist in our number system. Alternate number systems allow 1/0 to exist at the expense of many useful properties of mathematics that (OC?) OP doesn’t seem to understand. Not everything in math has to make sense: we simply gave ourselves some set rules, and then built up a system off the consequences of those rules. If 1/0 cannot exist within those rules, then that’s it. If you’re going to argue against centuries of mathematical advancements then so be it, I can’t stop you, but it’s pretty obviously a losing battle.

              • @[email protected]
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                22 years ago

                Dude you picked an obscure sub field of mathematics defined by looping a set around a sphere in order to make both positive and negative infinity equal. That’s like saying sea food is bad because I asked something allergic to shell fish if they like it.

      • @[email protected]
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        12 years ago

        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?

      • @[email protected]
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        22 years ago

        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.

        • Doctor xNo
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          02 years ago

          Nothing in my phone is either infinite, nor negative.

          • @[email protected]
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            22 years ago

            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

            • Doctor xNo
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              02 years ago

              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.

              • @[email protected]
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                2 years ago

                You did many. Well, yeah, I honestly don’t believe you as a matter of fact. By our conversation: You don’t seem to know what a limit is, you don’t know the difference between natural and real numbers, you don’t know the formal definition of infinity, and you don’t know any applications of calculus, the subject built around that definition. So yeah, I have a really hard time believing that you’ve ever taken a college level math class, or even paid good attention in your highschool math classes either.

                • Doctor xNo
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                  02 years ago

                  Says the guy who claimed infinite was ever-expanding. 😅

                  • @[email protected]
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                    22 years ago

                    That’s how you approach it, with ever increasing real numbers. Take a calculus class, I’m done teaching you for free