Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • World
  • Users
  • Groups
Skins
  • Light
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (No Skin)
  • No Skin
Collapse
Code Project
  1. Home
  2. The Lounge
  3. pi

pi

Scheduled Pinned Locked Moved The Lounge
graphicsquestion
107 Posts 35 Posters 3 Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • J Jeremy Falcon

    It still didn't address the why. If it did, I didn't understand it. :) Jeremy Falcon

    C Offline
    C Offline
    Chris Maunder
    wrote on last edited by
    #23

    Change the question around. Instead of asking "why can't Pi be expressed as P/Q", ask yourself "Why should any random real number (ie not an integer, not a complex number) be lucky enough to be expressable as P/Q" To have a number be able to be expressed, exactly, as a ratio of two other numbers is pretty remarkable. cheers, Chris Maunder

    CodeProject.com : C++ MVP

    1 Reply Last reply
    0
    • J Jeremy Falcon

      Super Lloyd wrote:

      do you mean never repeat?

      I was under the impression it was infinite, just as 1/3 would also be. Jeremy Falcon

      S Offline
      S Offline
      Super Lloyd
      wrote on last edited by
      #24

      Ha.. but in that case it could be expressed as simple rational such as: big number divided by big power of ten. And why that couldn't be I hear you ask? 1st it would be funny that 10 would be a relevant number for a circle but why not.... Anyway, while I do not know the reason for that myself I could argue that this guy Ferdinand von Lindeman[^] proved PI was transcendental (no solution of any polynome with ration parameter), hence it obviously never repeat

      J 1 Reply Last reply
      0
      • M Marc Clifton

        Jeremy Falcon wrote:

        What makes it go on forever?

        It's a number that is computed by an infinite series of smaller and smaller parts. For example, look at this.[^] Besides a lot of complicated equations, there's this very simple one: pi/4 = 1 - 1/3 + 1/5 - 1/7 ... You can see how the series is infinite, but smaller and smaller. So that's what makes it go on forever, and the resulting number is irrational, as discussed in the previous posts. Marc Pensieve Functional Entanglement vs. Code Entanglement Static Classes Make For Rigid Architectures

        C Offline
        C Offline
        Chris Maunder
        wrote on last edited by
        #25

        Marc Clifton wrote:

        So that's what makes it go on forever

        Actually not quite. Infinite series can easily add up to a rational number, or even an integer. 1/2 + 1/4 + 1/8 + ... = 1 cheers, Chris Maunder

        CodeProject.com : C++ MVP

        -- modified at 22:38 Thursday 16th March, 2006

        M 1 Reply Last reply
        0
        • V Vikram A Punathambekar

          Super Lloyd wrote:

          PI is very special, it's a not even a real such as SQRT(2).

          What do you mean? :wtf: Of course PI is a real number! The definition of a real number is that it's square should be nonnegative. And PI * PI is nonnegative. Cheers, Vikram.


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

          C Offline
          C Offline
          code frog 0
          wrote on last edited by
          #26

          Any number squared would be non-negative...:~

          A Plain English signature. Code-frog System Architects, Inc.

          J L V 3 Replies Last reply
          0
          • C Chris Maunder

            Marc Clifton wrote:

            So that's what makes it go on forever

            Actually not quite. Infinite series can easily add up to a rational number, or even an integer. 1/2 + 1/4 + 1/8 + ... = 1 cheers, Chris Maunder

            CodeProject.com : C++ MVP

            -- modified at 22:38 Thursday 16th March, 2006

            M Offline
            M Offline
            Marc Clifton
            wrote on last edited by
            #27

            Chris Maunder wrote:

            Infinite series can easily add up to a rational number, or even an integer.

            Ah, good point. I better stick to programming. :) Marc Pensieve Functional Entanglement vs. Code Entanglement Static Classes Make For Rigid Architectures

            1 Reply Last reply
            0
            • M Marc Clifton

              Jeremy Falcon wrote:

              What makes it go on forever?

              It's a number that is computed by an infinite series of smaller and smaller parts. For example, look at this.[^] Besides a lot of complicated equations, there's this very simple one: pi/4 = 1 - 1/3 + 1/5 - 1/7 ... You can see how the series is infinite, but smaller and smaller. So that's what makes it go on forever, and the resulting number is irrational, as discussed in the previous posts. Marc Pensieve Functional Entanglement vs. Code Entanglement Static Classes Make For Rigid Architectures

              J Offline
              J Offline
              Jeremy Falcon
              wrote on last edited by
              #28

              Marc Clifton wrote:

              You can see how the series is infinite, but smaller and smaller.

              I got all of that stuff. But it doesn't explain why the series exist in the first place. Fortunately, I think I got enough info from the fine folks at CP to help me set out a course to improve my understanding on it. I'm just not there yet. :) Jeremy Falcon

              7 1 Reply Last reply
              0
              • S Super Lloyd

                Ha.. but in that case it could be expressed as simple rational such as: big number divided by big power of ten. And why that couldn't be I hear you ask? 1st it would be funny that 10 would be a relevant number for a circle but why not.... Anyway, while I do not know the reason for that myself I could argue that this guy Ferdinand von Lindeman[^] proved PI was transcendental (no solution of any polynome with ration parameter), hence it obviously never repeat

                J Offline
                J Offline
                Jeremy Falcon
                wrote on last edited by
                #29

                I'm getting the impression I need to hit the books again. :-D Jeremy Falcon

                A 1 Reply Last reply
                0
                • 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

                  S Offline
                  S Offline
                  Shog9 0
                  wrote on last edited by
                  #30

                  I haven't had anywhere near enough to drink. Can we start with something a little easier, like "what is the length of a piece of string"? :-O

                  Now taking suggestions for the next release of CPhog...

                  J 1 Reply Last reply
                  0
                  • C code frog 0

                    Any number squared would be non-negative...:~

                    A Plain English signature. Code-frog System Architects, Inc.

                    J Offline
                    J Offline
                    Joey Bloggs
                    wrote on last edited by
                    #31

                    Only 'real' numbers. There is a whole branch of mathematics that deals with SQRT(-1) these are called 'imaginary' numbers.

                    1 Reply Last reply
                    0
                    • S Shog9 0

                      I haven't had anywhere near enough to drink. Can we start with something a little easier, like "what is the length of a piece of string"? :-O

                      Now taking suggestions for the next release of CPhog...

                      J Offline
                      J Offline
                      Jeremy Falcon
                      wrote on last edited by
                      #32

                      :) Simple, that would be 4. Next please. Jeremy Falcon

                      R 1 Reply Last reply
                      0
                      • C code frog 0

                        Any number squared would be non-negative...:~

                        A Plain English signature. Code-frog System Architects, Inc.

                        L Offline
                        L Offline
                        Luis Alonso Ramos
                        wrote on last edited by
                        #33

                        Those imaginary numbers (not real) are the i you see sometimes. It's sqrt(-1). Sometimes you can see numbers writen as a + b_**i**_, which have a real and an imaginary part. You can read more about them here[^] -- LuisR


                        Luis Alonso Ramos Intelectix - Chihuahua, Mexico Not much here: My CP Blog!

                        The amount of sleep the average person needs is five more minutes. -- Vikram A Punathambekar, Aug. 11, 2005

                        1 Reply Last reply
                        0
                        • C code frog 0

                          Any number squared would be non-negative...:~

                          A Plain English signature. Code-frog System Architects, Inc.

                          V Offline
                          V Offline
                          Vikram A Punathambekar
                          wrote on last edited by
                          #34

                          code-frog wrote:

                          Any number squared would be non-negative

                          Not imaginary numbers, like i. By definition, i * i = -1. Cheers, Vikram.


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

                          R 1 Reply Last reply
                          0
                          • S Super Lloyd

                            As Chris Munder said, it's a Transcendental number[^], much more uncommon than mere real number.

                            V Offline
                            V Offline
                            Vikram A Punathambekar
                            wrote on last edited by
                            #35

                            Super Lloyd wrote:

                            As Chris Munder said, it's a Transcendental number[^], much more uncommon than mere real number.

                            Erm, I never disagreed with that. You said PI is not real, and I only said it is. Cheers, Vikram.


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

                            S 1 Reply Last reply
                            0
                            • J Jeremy Falcon

                              It still didn't address the why. If it did, I didn't understand it. :) Jeremy Falcon

                              V Offline
                              V Offline
                              Vikram A Punathambekar
                              wrote on last edited by
                              #36

                              Jeremy Falcon wrote:

                              It still didn't address the why.

                              It simply is. Go in peace. Be. Cheers, Vikram.


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

                              1 Reply Last reply
                              0
                              • V Vikram A Punathambekar

                                code-frog wrote:

                                Any number squared would be non-negative

                                Not imaginary numbers, like i. By definition, i * i = -1. Cheers, Vikram.


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

                                R Offline
                                R Offline
                                Ryan Binns
                                wrote on last edited by
                                #37

                                Vikram A Punathambekar wrote:

                                By definition, i * i = -1

                                Thankyou! Someone who gets the definition correct! :-D I see most people say that i = sqrt(-1), which is NOT correct - it implies that i2 = 1

                                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"

                                V C 2 Replies Last reply
                                0
                                • 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

                                  R Offline
                                  R Offline
                                  Ryan Binns
                                  wrote on last edited by
                                  #38

                                  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"

                                  J 1 Reply Last reply
                                  0
                                  • R Ryan Binns

                                    Vikram A Punathambekar wrote:

                                    By definition, i * i = -1

                                    Thankyou! Someone who gets the definition correct! :-D I see most people say that i = sqrt(-1), which is NOT correct - it implies that i2 = 1

                                    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"

                                    V Offline
                                    V Offline
                                    Vikram A Punathambekar
                                    wrote on last edited by
                                    #39

                                    Ryan Binns wrote:

                                    I see most people say that i = sqrt(-1), which is NOT correct - it implies that i2 = 1

                                    Uh, how? If you say

                                    i = SQRT(-1)

                                    squaring both sides will give you

                                    i * i = -1

                                    How does i = sqrt(-1) imply i2 = 1 ? Cheers, Vikram.


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

                                    R 1 Reply Last reply
                                    0
                                    • 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

                                      D Offline
                                      D Offline
                                      Diagon Alley
                                      wrote on last edited by
                                      #40

                                      I always thought it was 22/7 atleast that was what my math teacher told me!! :doh: If you need a hammer get C and shut up. If you need a nail gun get C++ and shut up. If you don't need *those* things (and good design should tell you) then by all means get a factory, factory, factory. --code-frog@codeproject

                                      D 1 Reply Last reply
                                      0
                                      • V Vikram A Punathambekar

                                        Super Lloyd wrote:

                                        As Chris Munder said, it's a Transcendental number[^], much more uncommon than mere real number.

                                        Erm, I never disagreed with that. You said PI is not real, and I only said it is. Cheers, Vikram.


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

                                        S Offline
                                        S Offline
                                        Super Lloyd
                                        wrote on last edited by
                                        #41

                                        it's a pure definition problem then? I think the issue here is the same as vegetable and fruit. Some people would say tomatoes is a fruit, some people would say it is not. And then they each refer to their own definition. Doens't matter too much. Anyway I will stick to my definition which means that PI is part of super set of the real (hence it is not a real number). And that Math teacher don't bother make the difference explicit until you are in advanced math studies....

                                        D V 2 Replies Last reply
                                        0
                                        • D Diagon Alley

                                          I always thought it was 22/7 atleast that was what my math teacher told me!! :doh: If you need a hammer get C and shut up. If you need a nail gun get C++ and shut up. If you don't need *those* things (and good design should tell you) then by all means get a factory, factory, factory. --code-frog@codeproject

                                          D Offline
                                          D Offline
                                          David Stone
                                          wrote on last edited by
                                          #42

                                          Observe: A Simple Proof that 22/7 exceeds Pi[^]. 22/7 is merely a convenient Diophantine approximation that people are taught in basic math so that they can have some frame of reference for Pi.

                                          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

                                          N D 2 Replies Last reply
                                          0
                                          Reply
                                          • Reply as topic
                                          Log in to reply
                                          • Oldest to Newest
                                          • Newest to Oldest
                                          • Most Votes


                                          • Login

                                          • Don't have an account? Register

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular
                                          • World
                                          • Users
                                          • Groups