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  3. Following on from yesterday's little puzzler.

Following on from yesterday's little puzzler.

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  • OriginalGriffO OriginalGriff

    It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

    "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

    Mircea NeacsuM Offline
    Mircea NeacsuM Offline
    Mircea Neacsu
    wrote on last edited by
    #5

    OriginalGriff wrote:

    It seem that many of us are convinced that -∞ is larger than 0

    That has me worried about the state of our profession! :omg: Disclaimer: I didn't read all of the >50 replies to your original message, considering the solution you posted in the ≈5th message as self-evident and not a reason for debate. After that point I just shook my head in disbelief. :sigh:

    Mircea

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    • R Rage

      I don't think anyone doubted that -1 is the greatest negative integer. It is just that the concept of "large negative" can be easily interpreted by "a number with a lot of figures and minus sign in front of it".

      Do not escape reality : improve reality !

      Mircea NeacsuM Offline
      Mircea NeacsuM Offline
      Mircea Neacsu
      wrote on last edited by
      #6

      How about -π: it has lots of figures and a minus sign :laugh:

      Mircea

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      • OriginalGriffO OriginalGriff

        It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

        "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

        L Offline
        L Offline
        Lost User
        wrote on last edited by
        #7

        Explain this: the sum of all positive integers on to infinity equals minus 1/12 The Great Debate Over Whether 1+2+3+4..+ ∞ = -1/12 | Smart News| Smithsonian Magazine[^]

        OriginalGriffO J 2 Replies Last reply
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        • L Lost User

          Explain this: the sum of all positive integers on to infinity equals minus 1/12 The Great Debate Over Whether 1+2+3+4..+ ∞ = -1/12 | Smart News| Smithsonian Magazine[^]

          OriginalGriffO Offline
          OriginalGriffO Offline
          OriginalGriff
          wrote on last edited by
          #8

          I can't explain that, it involves division and I can't do that. :-D

          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt AntiTwitter: @DalekDave is now a follower!

          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
          "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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          • Mircea NeacsuM Mircea Neacsu

            How about -π: it has lots of figures and a minus sign :laugh:

            Mircea

            N Offline
            N Offline
            Nelek
            wrote on last edited by
            #9

            You are evil... :laugh: :laugh: :laugh:

            M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.

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            • OriginalGriffO OriginalGriff

              It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

              "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

              N Offline
              N Offline
              Nelek
              wrote on last edited by
              #10

              In my case (non native english speaker) "large" is for me more associated with size, not value. That's why I would usually think first on the biggest module in negative, meaning -∞. But... as I have had a lot of such tricky questions, I tend to wait a second, put back the obvious answer and pay a lot of more attention to the wording while activating the paranoic mode. So at the end I found the right solution.

              M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.

              M 1 Reply Last reply
              0
              • OriginalGriffO OriginalGriff

                It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                R Offline
                R Offline
                raddevus
                wrote on last edited by
                #11

                And, as I stated in JavaScript:

                -1 > Number.NEGATIVE_INFINITY; // true

                If you only believe C# then:

                Console.WriteLine(-1 > Double.NegativeInfinity ); // true

                Since programming languages do model mathematics I think this should help to understand this. However, I am no mathematician and defer to anyone with a Math degree on this. :rolleyes:

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                • OriginalGriffO OriginalGriff

                  It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                  "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                  P Offline
                  P Offline
                  PIEBALDconsult
                  wrote on last edited by
                  #12

                  OriginalGriff wrote:

                  * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                  Well that's bullpucky. I've been looking around and I have seen only circular definitions/properties for "positive" -- first they assume that zero is not positive and then they define a property which may or may not be consistent with that definition. Zero is positive. And so am I.

                  0 J 2 Replies Last reply
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                  • P PIEBALDconsult

                    OriginalGriff wrote:

                    * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                    Well that's bullpucky. I've been looking around and I have seen only circular definitions/properties for "positive" -- first they assume that zero is not positive and then they define a property which may or may not be consistent with that definition. Zero is positive. And so am I.

                    0 Offline
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                    0x01AA
                    wrote on last edited by
                    #13

                    If 0 should be positive (or negative), then the whole chemistry/quantum theory has a problem? [Edit] Limit value considerations are a different topic, whether one approaches a limit value from negative or positive

                    1 Reply Last reply
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                    • OriginalGriffO OriginalGriff

                      It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                      "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                      L Offline
                      L Offline
                      Lost User
                      wrote on last edited by
                      #14

                      Yes. The Mariana Trench is deeper than Mount Everest is high. But that doesn't mean the trench is "bigger".

                      "Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

                      P 1 Reply Last reply
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                      • L Lost User

                        Yes. The Mariana Trench is deeper than Mount Everest is high. But that doesn't mean the trench is "bigger".

                        "Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

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                        PIEBALDconsult
                        wrote on last edited by
                        #15

                        Mount Everest isn't high at all; it's at ground level.

                        A 1 Reply Last reply
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                        • OriginalGriffO OriginalGriff

                          It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                          J Offline
                          J Offline
                          jmaida
                          wrote on last edited by
                          #16

                          it makes sense. the problem is the term "largest negative integer". Does the "largest non-negative integer" = infinity ? if so, then the reverse would be "largest negative integer" which by symmetry would be -infinity. The problem is mixing language and mathematics. 3rd grade math revisited.

                          "A little time, a little trouble, your better day" Badfinger

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                          • OriginalGriffO OriginalGriff

                            It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                            "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                            T Offline
                            T Offline
                            theoldfool
                            wrote on last edited by
                            #17

                            Quote:

                            1 was the last, so it's the smallest positive number. Everyone here has agreed on that!

                            Not the flat earthers. (they abound) :laugh:

                            >64 It’s weird being the same age as old people.

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                            0
                            • OriginalGriffO OriginalGriff

                              It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                              "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                              M Offline
                              M Offline
                              Marc Clifton
                              wrote on last edited by
                              #18

                              And again I balk. "greater than" and "largest" are not synonymous for me, and "largest", when speaking of negative numbers, is non-sensical because negative things don't have "largeness." :rolleyes:

                              Latest Articles:
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                              OriginalGriffO 1 Reply Last reply
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                              • OriginalGriffO OriginalGriff

                                It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                                "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                                Richard Andrew x64R Offline
                                Richard Andrew x64R Offline
                                Richard Andrew x64
                                wrote on last edited by
                                #19

                                I never doubted for a minute that you were correct, I just didn't think hard enough about it.

                                The difficult we do right away... ...the impossible takes slightly longer.

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                                • L Lost User

                                  Explain this: the sum of all positive integers on to infinity equals minus 1/12 The Great Debate Over Whether 1+2+3+4..+ ∞ = -1/12 | Smart News| Smithsonian Magazine[^]

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                                  jschell
                                  wrote on last edited by
                                  #20

                                  Paul6124 wrote:

                                  on to infinity equals minus 1/12

                                  As it says "only equals -1/12 because the mathematicians redefined the equal sign." You can also prove other things by ignoring and/or redefining terms and assumptions in mathematics. For example it is generally accepted that you cannot prove in Euclidean geometry that parallel lines do not intersect. However you can prove that if you assume that a right triangle has a 90 degree angle. So trade one assumption for another. So in terms of the prior post one can redefine the problem by asserting that negatives can be bigger if the absolute value is bigger. Thus redefining what 'bigger' means in terms of the standard for Number Theory.

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                                  • P PIEBALDconsult

                                    OriginalGriff wrote:

                                    * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                                    Well that's bullpucky. I've been looking around and I have seen only circular definitions/properties for "positive" -- first they assume that zero is not positive and then they define a property which may or may not be consistent with that definition. Zero is positive. And so am I.

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                                    jschell
                                    wrote on last edited by
                                    #21

                                    PIEBALDconsult wrote:

                                    Well that's bullpucky. I've been looking around and I have seen only circular definitions/properties for "positive"

                                    Not sure I understand your point. There are many assumptions and term definitions in mathematics. Proofs are then based on both of those. If the terms/definitions are not accepted/understood then the proof becomes invalid (at least for one person.) I am rather certain that negative and positive are and always have been definitions. No one attempts to prove them. Not to mention of course that semantics of language makes this even more confusing. For example provide a definition for the word 'table' which includes all tables but excludes all other objects. Because of that people are always going to be limited in attempting to provide exact definitions. Including in mathematics.

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                                    • OriginalGriffO OriginalGriff

                                      It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                                      "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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                                      jmaida
                                      wrote on last edited by
                                      #22

                                      check out this puzzlement Missing dollar riddle - Wikipedia[^]

                                      "A little time, a little trouble, your better day" Badfinger

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                                      • M Marc Clifton

                                        And again I balk. "greater than" and "largest" are not synonymous for me, and "largest", when speaking of negative numbers, is non-sensical because negative things don't have "largeness." :rolleyes:

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                                        OriginalGriff
                                        wrote on last edited by
                                        #23

                                        So ... you can't have a "large student debt"? :laugh:

                                        "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt AntiTwitter: @DalekDave is now a follower!

                                        "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                                        "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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                                        • OriginalGriffO OriginalGriff

                                          It seem that many of us are convinced that -∞ is larger than 0 so I thought I'd try and explain why that isn't the case, even though it does seem to make sense. Let's look at what "greater than" actually means (in all cases I'll use integers but it's exactly the same for floating point numbers). 1 is greater than 0, 2 is greater than both 1 and 0, 3 is greater than 2, 1, and 0, and so on: the general case is "if you add a positive number* to a value, you get a value that is greater than the original": X + n > X where n is any positive number. Similarly, "less than" comes down to: X - n < X where n is any positive number. And it works: 2 > 1 because 1 + 1 == 2; 3 > 1 because 1 + 2 == 3; ... 1 < 2 because 2 - 1 == 1; 1 < 3 because 3 - 2 == 1; ... And we can use "greater than" and "Less than" for find maxima and minima for a set of numbers. We can find the smallest positive number by taking any positive number as a starting point and repeatedly subtracting 1 until we reach a non-positive value (which will be zero): 1 was the last, so it's the smallest positive number. Everyone here has agreed on that! But when we look for the largest negative number it seems that some people are mistaking the absolute magnitude of a value for the value itself, and saying that the largest negative number is -∞ But that's not the case: just as numbers get smaller as you approach 0 from the positive side, they don't start getting bigger again as you move away into the negative side: 1 > 0; 1 > -1; 1 > -2 Slide that sideways and it's clearer for negative numbers: 0 > -1; 0 > -2; 0 > -3 -1 > -2; -1 > -3; -1 > -4 So to find the largest negative number, we start with any negative number as a starting point and repeatedly adding 1 until we reach a non-negative value (which will be zero): -1 was the last, so that's the largest negative number. Make sense? * Zero is neither positive nor negative because the definition of both those terms stems from the direction of X from 0.

                                          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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                                          CPallini
                                          wrote on last edited by
                                          #24

                                          :thumbsup: Bringing QA experience to the Lounge!

                                          "In testa che avete, Signor di Ceprano?" -- Rigoletto

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