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pi

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  • C Chris Maunder

    Hang on. If the definition if i is i^2 = -1 then i = +/- sqrt(-1) Nothing wrong with i := sqrt(-1) cheers, Chris Maunder

    CodeProject.com : C++ MVP

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    Vikram A Punathambekar
    wrote on last edited by
    #70

    Chris Maunder wrote:

    If the definition if i is i^2 = -1 then i = +/- sqrt(-1)

    I thought that was implicit. SQRT(36) is -6 as much as it is 6. Cheers, Vikram.


    I don't know and you don't either. Militant Agnostic

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    • C Chris Maunder

      Hang on. If the definition if i is i^2 = -1 then i = +/- sqrt(-1) Nothing wrong with i := sqrt(-1) cheers, Chris Maunder

      CodeProject.com : C++ MVP

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      Vikram A Punathambekar
      wrote on last edited by
      #71

      Chris Maunder wrote:

      If the definition if i is i^2 = -1 then i = +/- sqrt(-1)

      I thought that was implicit. SQRT(36) is -6 as much as it is 6. Cheers, Vikram.


      I don't know and you don't either. Militant Agnostic

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      • V Vikram A Punathambekar

        Chris Maunder wrote:

        If the definition if i is i^2 = -1 then i = +/- sqrt(-1)

        I thought that was implicit. SQRT(36) is -6 as much as it is 6. Cheers, Vikram.


        I don't know and you don't either. Militant Agnostic

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        Chris Maunder
        wrote on last edited by
        #72

        Right - every square root has two solutions so you can't define a single quantity as the solution to a square root, otherwise you'd be implying sqrt(-1) = -sqrt(-1). And that would cause a few problems ;) cheers, Chris Maunder

        CodeProject.com : C++ MVP

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        • S Super Lloyd

          if complex number don't coun't, what's the point of your definition then? :omg: :laugh:

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          David Stone
          wrote on last edited by
          #73

          The set of complex numbers is a superset of the set of real numbers. So real numbers are included in the set of complex numbers. Unreal numbers are just the set of all numbers that are not in the reals.

          They dress you up in white satin, And give you your very own pair of wings In August and Everything After

          I'm after everything

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          • C Chris Maunder

            Right - every square root has two solutions so you can't define a single quantity as the solution to a square root, otherwise you'd be implying sqrt(-1) = -sqrt(-1). And that would cause a few problems ;) cheers, Chris Maunder

            CodeProject.com : C++ MVP

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            Vikram A Punathambekar
            wrote on last edited by
            #74

            Chris Maunder wrote:

            every square root has two solutions so you can't define a single quantity as the solution to a square root

            Except, of course, SQRT(0). ;P Cheers, Vikram.


            I don't know and you don't either. Militant Agnostic

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            • R Ryan Binns

              Aah. Ok. Perhaps you could explain that to every maths lecturer I ever had. 5 years of maths, and they all said the same thing :~

              Ryan

              "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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              David Stone
              wrote on last edited by
              #75

              That really sucks. Those profs should be dragged out back and shot. (In the mathematical sense, of course. ;P)

              They dress you up in white satin, And give you your very own pair of wings In August and Everything After

              I'm after everything

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              • D David Stone

                The set of complex numbers is a superset of the set of real numbers. So real numbers are included in the set of complex numbers. Unreal numbers are just the set of all numbers that are not in the reals.

                They dress you up in white satin, And give you your very own pair of wings In August and Everything After

                I'm after everything

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                Super Lloyd
                wrote on last edited by
                #76

                hu.... ??? for the remark my remark was related the Vikram definition of real number. Vikram definition: number whose square value is not negative.

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                • V Vikram A Punathambekar

                  Chris Maunder wrote:

                  every square root has two solutions so you can't define a single quantity as the solution to a square root

                  Except, of course, SQRT(0). ;P Cheers, Vikram.


                  I don't know and you don't either. Militant Agnostic

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                  Chris Maunder
                  wrote on last edited by
                  #77

                  There's always one... :rolleyes: cheers, Chris Maunder

                  CodeProject.com : C++ MVP

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                  • J Jeremy Falcon

                    I thought you could still have an infinite irrational number though. Or, is that not the case? Jeremy Falcon

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                    Jorgen Sigvardsson
                    wrote on last edited by
                    #78

                    That's one of these things one can't be certain of. I think. What's to say that pi doesn't plane out on zero decimals halfway to infinity? :)

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                    • J Jeremy Falcon

                      I'm trying to find a good way to explain why pi is infinite (not what it is). And I'm drawing up blanks. Any math gurus care to shed me some light please? Jeremy Falcon

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                      V 0
                      wrote on last edited by
                      #79

                      Isn't Pi a coëfficiënt for the circle? I'm thinking that it keeps on going because a real circle doesn't exist, it's always a rounding of some polygone. The more decimals you have, the closer you get to the real circle and because a real circle doesn't exist, you can keep on going. But that's just a theory :-). There are other rational numbers you know: e, root of 2, ... :-D No hurries, no worries. -- modified at 2:25 Friday 17th March, 2006

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                      • D David Stone

                        That really sucks. Those profs should be dragged out back and shot. (In the mathematical sense, of course. ;P)

                        They dress you up in white satin, And give you your very own pair of wings In August and Everything After

                        I'm after everything

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                        Ryan Binns
                        wrote on last edited by
                        #80

                        David Stone wrote:

                        Those profs should be dragged out back and shot. (In the mathematical sense, of course. ;P)

                        Of course. We should mathematically prove that the shot will kill them before firing it ;)

                        Ryan

                        "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                        • V Vikram A Punathambekar

                          Chris Maunder wrote:

                          every square root has two solutions so you can't define a single quantity as the solution to a square root

                          Except, of course, SQRT(0). ;P Cheers, Vikram.


                          I don't know and you don't either. Militant Agnostic

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                          Ryan Binns
                          wrote on last edited by
                          #81

                          Vikram A Punathambekar wrote:

                          Except, of course, SQRT(0).

                          You mean you can't have -0 ? :rolleyes: The Intel 387 maths coprocessor could. It differentiated between +0 and -0 :~

                          Ryan

                          "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                          • D David Stone

                            You're getting confused here because math people don't like to hear that a number is infinite. The term you're looking for is infinitely repeating. :)

                            They dress you up in white satin, And give you your very own pair of wings In August and Everything After

                            I'm after everything

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                            Jeremy Falcon
                            wrote on last edited by
                            #82

                            :-D Thanks for the tip. Jeremy Falcon

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                            • 7 73Zeppelin

                              I think most people above didn't approach their explanation as follows: Pi is an "infinitely long" number due to its transcendental nature. I will explain why I put that in quotes. That is, there is no closed algebraic function whose solution yields exactly pi nor are there two whole numbers whose ratio expresses pi exactly. Consequently, we must use an approximation to pi. The precision of the approximation is limited to the computing power and time you want to spend on calculating pi. That is why the approximation to pi is infinitely long.

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                              Jeremy Falcon
                              wrote on last edited by
                              #83

                              Ok, that makes perfect sense. Thanks. Jeremy Falcon

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                              • R Ryan Binns

                                Jeremy Falcon wrote:

                                I'm trying to find a good way to explain why pi is infinite (not what it is).

                                Because. :)

                                Ryan

                                "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                                Jeremy Falcon
                                wrote on last edited by
                                #84

                                Why not? :) I was asked by someone btw, and I didn't have an answer. Jeremy Falcon

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                                • R Roger Wright

                                  Pi is irrational, like my ex-wife. Fortunately, neither is infinite. Both go on forever, without end, for no good reason, never repeating any sensible pattern. Thank God that Pi can't hold a credit card. "...a photo album is like Life, but flat and stuck to pages." - Shog9

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                                  Jeremy Falcon
                                  wrote on last edited by
                                  #85

                                  Roger Wright wrote:

                                  Thank God that Pi can't hold a credit card.

                                  :-D Jeremy Falcon

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                                  • V Vivek Rajan

                                    Let me approach this another way. You are just wondering - why the heck must a simple thing such as the ratio of the circumference to the diameter be so darn complex. For gawds sake it is a ratio ! Assuming you are able to measure both the circumference and diameter to a great precision with an electron microscope thing. Then PI would simply be c/d - right ? So why on earth is Pi so enormously complicated. Why is Pi irrational/ trancedental/ math-mumbojumbo word - when both circumference and diameter are simple, measurable real numbers. The answer to that lies in the fact that there is no such thing as a measurement. We humans cannot measure, we can only count. We can count inches, millimeters, microns, nanometers and call it a measurement, but we are fooling no one. Still, you wonder how did this monstrosity creep up on us. Why cant PI be something simpler like a square root (3). I think the best answer I have heard so far is "yeah, it might be a really simple number in another universe parallel to ours, we might have just got unlucky in our universe". The moment I heard this from a scifi geek buddy - I understood I had hit a culdesac. There was no point trying to get to the root of this without some tools such as a wormhole-stargate.

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                                    Jeremy Falcon
                                    wrote on last edited by
                                    #86

                                    Vivek Rajan wrote:

                                    Assuming you are able to measure both the circumference and diameter to a great precision with an electron microscope thing. Then PI would simply be c/d - right ? So why on earth is Pi so enormously complicated. Why is Pi irrational/ trancedental/ math-mumbojumbo word - when both circumference and diameter are simple, measurable real numbers.

                                    Bingo. Jeremy Falcon

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                                    • V V 0

                                      Isn't Pi a coëfficiënt for the circle? I'm thinking that it keeps on going because a real circle doesn't exist, it's always a rounding of some polygone. The more decimals you have, the closer you get to the real circle and because a real circle doesn't exist, you can keep on going. But that's just a theory :-). There are other rational numbers you know: e, root of 2, ... :-D No hurries, no worries. -- modified at 2:25 Friday 17th March, 2006

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                                      Jeremy Falcon
                                      wrote on last edited by
                                      #87

                                      V. wrote:

                                      But that's just a theory.

                                      Thanks for the thought. Jeremy Falcon

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                                      • J Jeremy Falcon

                                        I'm trying to find a good way to explain why pi is infinite (not what it is). And I'm drawing up blanks. Any math gurus care to shed me some light please? Jeremy Falcon

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                                        Joshua Nussbaum
                                        wrote on last edited by
                                        #88

                                        I always think of it like this: The area of a circle was calculated in ancient times by fitting smaller squares within the circle. The more squares you add the closer you approach the correct area. Since you can always add more squares, you can always get a more finite answer. but never one that is definate.. cause you can always add more smaller squares which would give more decimal places to the end of pi. hope that makes some sense ;) 60% of statistics are made up on the spot

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                                        • J Jeremy Falcon

                                          I'm trying to find a good way to explain why pi is infinite (not what it is). And I'm drawing up blanks. Any math gurus care to shed me some light please? Jeremy Falcon

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                                          Ashley van Gerven
                                          wrote on last edited by
                                          #89

                                          A little bit off topic - but maybe of interest; a savant called Daniel Tammit is literally in love with pi. He memorised pi to 22,500 decimal places :omg: I think he said it's the most beautiful number there is - on the BBC documentary The Boy With The Incredible Brain[^] Some other info here: http://www.mymultiplesclerosis.co.uk/misc/danieltammet.html[^] "In March of 2004 Daniel had his own surprise, in Oxford, England, he would recite the number Pi to 22,500 decimal places, in public in front of a team of invigilators to verify his accuracy. After just over five hours he had completed this extraordinary memory feat."

                                          "... This man is obviously a psychotic." "We-he-ell, uh, I'd like to hold off judgement on a thing like that, sir, until all the facts are in." (Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb)

                                          ~ ScrollingGrid (cross-browser freeze-header control)

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