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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

    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
      0
      • 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
        0 Offline
        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

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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

            P Offline
            P Offline
            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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                • 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:
                  A Lightweight Thread Safe In-Memory Keyed Generic Cache Collection Service A Dynamic Where Implementation for Entity Framework

                  OriginalGriffO 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

                    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[^]

                      J Offline
                      J Offline
                      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.

                      L 2 Replies Last reply
                      0
                      • 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.

                        J Offline
                        J Offline
                        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

                          J Offline
                          J Offline
                          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

                          A 1 Reply Last reply
                          0
                          • 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:

                            Latest Articles:
                            A Lightweight Thread Safe In-Memory Keyed Generic Cache Collection Service A Dynamic Where Implementation for Entity Framework

                            OriginalGriffO Offline
                            OriginalGriffO Offline
                            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

                            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

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                              C Offline
                              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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                              • 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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                                Member 10652083
                                wrote on last edited by
                                #25

                                Maybe - if you change "non-positive value" in your last sentence to "non-negative value".

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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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                                  haughtonomous
                                  wrote on last edited by
                                  #26

                                  I'm not sure about your explanation, but I sense you are making the mistake I referred to yesterday, viz. basing your argument on the way number theory is implemented in the computer languages with which you are familiar, rather than on formal number theory itself. To answer the question we need the advice of pure mathemeticians on how magnitude of negative numbers is defined. How computers deal with it is clouded, as usual, by practicalities and compromise. However I doubt if there are any pure mathematicians lurking in this forum!

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                                  • M Member 10652083

                                    Maybe - if you change "non-positive value" in your last sentence to "non-negative value".

                                    OriginalGriffO Offline
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                                    OriginalGriff
                                    wrote on last edited by
                                    #27

                                    Oops! Fixed :thumbsup:

                                    "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

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                                      Alister Morton
                                      wrote on last edited by
                                      #28

                                      e^iπ is the largest negative integer, I'd say.

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                                      • A Alister Morton

                                        e^iπ is the largest negative integer, I'd say.

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                                        Gary Wheeler
                                        wrote on last edited by
                                        #29

                                        e_i_π FTFY.

                                        Software Zen: delete this;

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                                        • G Gary Wheeler

                                          e_i_π FTFY.

                                          Software Zen: delete this;

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                                          Alister Morton
                                          wrote on last edited by
                                          #30

                                          Eye thang ewe. ;-)

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