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1 = 0

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  • M Marc Clifton

    Ah, the ol' divide by zero trick. I think my math teacher did that when I was in 8th grade. Almost 40 years ago. And I'm sure it's older than that. ;) Marc

    Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project!

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    Corporal Agarn
    wrote on last edited by
    #33

    Since I remember it from math about that time it has to be old. :-D How can I remember this but cannot find my car keys?

    Mongo: Mongo only pawn... in game of life.

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    • H HobbyProggy

      Dominic Burford wrote:

      x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y.

      Wrong... aint it? x2 -y2 / (x-y) => x+y xy -y2 / (x-y) => y+y xy / x-y => 1*1/1-1 => (actually how could you divide this when there is a minus...) y2 / x-y => y/x-1 => (actually how could you devide this when there is a minus...) But i guess thats bullshit 2 because it "should"? be x2/x-y - y2/x-y which ruins everything :) Okay screw everything... you are wrong, thats all i can say :)

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      kiLLe_512
      wrote on last edited by
      #34

      if(!string.IsNullOrEmpty(this.signature)) ftfy

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      • Richard DeemingR Richard Deeming

        Take your pick: How Can 0.999... = 1? | Purplemath[^] For example:

          x = 0.999...
        

        10x = 9.999...
        10x - x = 9.000...
        9x = 9
        x = 1

        EDIT: As Nagy said[^], 2+ hours ago.


        "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

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        kiLLe_512
        wrote on last edited by
        #35

        That's bloody brilliant!

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        • H HobbyProggy

          The only thing i can agree with is that 1 != 3/3 (at least not exactly) because 1/3 is 0,333... and multiplied with 3 it is just 0,99999.... which is technically 1 but not 100%

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          Florgenator
          wrote on last edited by
          #36

          Actually, yes 0.9999..... is in fact 1: x = 0.99999.... 10 x = 9.999999.... multiply by 10 10 x = 9 + 0.99999.... split right side into arithmetic expression 10 x = 9 + x replace 0.9999.... with "x" 9 x = 9 subtract "x" from both sides x = 1 divide by 9. without dividing by "0"

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          • K kiLLe_512

            if(!string.IsNullOrEmpty(this.signature)) ftfy

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            HobbyProggy
            wrote on last edited by
            #37

            Thank god signature is not an object you first have to convert .ToString() right?

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            • D Dominic Burford

              x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

              "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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              MKJCP
              wrote on last edited by
              #38

              If you divide by zero you get sucked into the mathematical black hole where all logic is lost. But if it were true that 1=0, would that simplify chip design? "A little knowledge is a dangerous thing, drink deeply or taste not."

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              • D Dominic Burford

                x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                BallsMcShaft
                wrote on last edited by
                #39

                The second statement is false. if x = y, then x2 does not equal xy; x to the second power equals xy. For example: if 1=1 then 1(2) does not equal 1(1) Bullshit from the start, not to mention the division by zero

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                • H HobbyProggy

                  The only thing i can agree with is that 1 != 3/3 (at least not exactly) because 1/3 is 0,333... and multiplied with 3 it is just 0,99999.... which is technically 1 but not 100%

                  Rules for the FOSW ![^]

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                  User 12150297
                  wrote on last edited by
                  #40

                  Am I the only one that doesn't see the issue that we are not dividing 1 by 3.... 1 = 3/3... If you're going to divide by 3 on the 1... wouldn't you need to also need to divide 3/3 by 3 also... 1/3 = (3/3)/3.... which would both be .03333... ??

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                  • D Dominic Burford

                    x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                    "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                    User 11955655
                    wrote on last edited by
                    #41

                    Sorry guys but second line is false its only true when x=1 or 2 x = y. Then x2 = xy is wrong if x=3 , xy=9 x2=6 6 !=9 you can't divide this way if its proper algebra left side is x2 - y2   2(x-y) ------- = ------ = 2 <- left side of the equation (x-y)        (x-y) and obviously you cant separate (x-y) from the right side (xy - y2)/(x-y) != y sorry guys example is flawed and 1 != 0

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                    • D Dominic Burford

                      x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                      "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                      spa_war
                      wrote on last edited by
                      #42

                      Unfortunately, this "proof" falls apart at the 2nd line. x2 = xy only holds true for 0, 2, and -2. The correct equation is x^2 = xy. Still, a pretty interesting use of mathematics in an attempt to destroy all of our beliefs in what is thought to be true. :thumbsup:

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                      • D Dominic Burford

                        x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                        "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                        mBuchwald
                        wrote on last edited by
                        #43

                        This appears to work, but only because you are dividing by zero since (x-y) is, by definition of the first line, equal to zero.

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                        • D Dominic Burford

                          x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                          "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                          Dominic Amann
                          wrote on last edited by
                          #44

                          huh? I don't think x = y implies x2 = xy. How did you get that?

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                          • H HobbyProggy

                            The only thing i can agree with is that 1 != 3/3 (at least not exactly) because 1/3 is 0,333... and multiplied with 3 it is just 0,99999.... which is technically 1 but not 100%

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                            willichan
                            wrote on last edited by
                            #45

                            HobbyProggy wrote:

                            because 1/3 is 0,333

                            No. 1/3 does not equal 0.333. 1/3 is APPROXIMATELY 0.333. and 0.99999 is not technically 1. It is APPROXIMATELY 1 There is even a different symbol for it. 1/3≈0.333 (1/3 is approximately equal to 0.333) 0.99999≈1 (0.99999 is approximately equal to 1)

                            Money makes the world go round ... but documentation moves the money.

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                            • Sander RosselS Sander Rossel

                              A high school teacher showed this to me some 10+ years back (feeling old now). All I can say is no.

                              Visit my blog at Sander's bits - Writing the code you need. Or read my articles at my CodeProject profile.

                              Simplicity is prerequisite for reliability. — Edsger W. Dijkstra

                              Regards, Sander

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                              James Curran
                              wrote on last edited by
                              #46

                              Quote:

                              A high school teacher showed this to me some 10+ years back (feeling old now).

                              10+ years is making you feel old? I saw that in high school 35+ years old..... (*) Even then, was able to figure out the flaw.

                              Truth, James

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                              • D Dominic Burford

                                x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                                "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                                Member_5893260
                                wrote on last edited by
                                #47

                                As has been pointed out here, at some point you're dividing erroneously. But, you can prove that 0 = any number you want, using the derivation of differential calculus, as described here[^]: if you plug numbers into the equation at stage 3, you can "prove" pretty much whatever you want to prove. But of course, math is a language, not reality - and you can speak nonsense in any language.

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                                • D Dominic Burford

                                  x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                                  "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                                  Member 11711973
                                  wrote on last edited by
                                  #48

                                  If 1 = 0, then 1 - 1 = 0 - 1, which means -1 = 0. Contradiction, so 1 = 0 can't be true.

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                                  • D Dominic Burford

                                    x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                                    "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                                    charleslbryant
                                    wrote on last edited by
                                    #49

                                    This is a code site so I wanted to prove this with C# and it fell apart for me.

                                    [TestMethod]
                                    public void TestMethod1()
                                    {
                                    //x = y
                                    //Assuming y = 5.
                                    var y = 5;

                                            var x = y;
                                    
                                            //Then x2 = xy
                                            Assert.AreEqual(x \* 2, x \* y); //Assert.AreEqual failed. Expected:<10>. Actual:<25>.
                                        }
                                    
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                                    • D Dominic Burford

                                      x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                                      "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                                      ClockMeister
                                      wrote on last edited by
                                      #50

                                      Sorry, that doesn't work. x2 is NOT equal to xy. That's like saying 2x = x*y which is ONLY true if x and y are both 2. Cute, but does not float.

                                      M 1 Reply Last reply
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                                      • D Dominic Burford

                                        x = y. Then x2 = xy. Subtract the same thing from both sides: x2 - y2 = xy - y2. Dividing by (x-y), obtain x + y = y. Since x = y, we see that 2 y = y. Thus 2 = 1, since we started with y nonzero. Subtracting 1 from both sides, 1 = 0. :wtf:

                                        "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

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                                        Vachaun22
                                        wrote on last edited by
                                        #51

                                        Well, the first problem with this is x = y then x2 = xy IFF x = y = 2 This was stated just above, but I didn't get that far when I was reading the comments...

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                                        • H HobbyProggy

                                          The only thing i can agree with is that 1 != 3/3 (at least not exactly) because 1/3 is 0,333... and multiplied with 3 it is just 0,99999.... which is technically 1 but not 100%

                                          Rules for the FOSW ![^]

                                          if(this.signature != "")
                                          {
                                          MessageBox.Show("This is my signature: " + Environment.NewLine + signature);
                                          }
                                          else
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                                          jschell
                                          wrote on last edited by
                                          #52

                                          HobbyProggy wrote:

                                          because 1/3 is 0,333..

                                          No it isn't. Mathematics defines and recognizes rational numbers. Mathematics defines and recognizes decimal numbers. They are two different things. Your equating them as the same does not remove certainly hundreds of years of mathematics and mathematicians that recognize and correctly differentiate the two. Certainly when I took mathematics courses that taught mathematics as it was implemented in computers they emphasized the assumptions and limitations of finite math. Actually understanding those assumptions and limitations makes the difference clear. Note clearly that in the above those were mathematics classes and not computer science classes. The difference is often where the former teaches the math and the later teaches how to use the computer. (Yes I took both.)

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