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Why Every Proof that .999... = 1 is Wrong

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Published on Apr 1, 2012

Take that, mathematics!
Original Video: http://www.youtube.com/watch?v=TINfzx...

  • Category

    Education

  • License

    Standard YouTube License

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All Comments (5,130)

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  • BanjoSoop

    BanjoSoop 4 hours ago

    I like "super" infinity. Great video!

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  • Kirsty Marsh

    Kirsty Marsh 7 hours ago

    never comment on what you think you know before the end of a video....

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  • Maj0rskillz

    Maj0rskillz 15 hours ago

    April fools

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    in reply to RadioactiveBBQ (Show the comment)
  • RadioactiveBBQ

    RadioactiveBBQ 18 hours ago

    I really hope this is just a prank or something because everything you're saying is absolutely wrong.

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  • doganoth05

    doganoth05 19 hours ago

    I think it was an april's fools mate ;)

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    in reply to Helmut Heise (Show the comment)
  • Kosekans

    Kosekans 20 hours ago

    1:30 The problem is that "0.000...1" is not a real number. Such a number doesn't exist. Try to understand what infinity or "infinitely many" Zeros after the decimal point means, before you talk about infinity or "super infinity" (not meant to be offensive).

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  • logedyftw

    logedyftw 20 hours ago

    I don't know if this video was an April fool's joke or not, but here is proof: 1-0.999 = 0, because the 0's go on infinitely, therefore meaning there isn't a 1 at the end. and if

    1-x=0, then x must be equal to 1.

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  • stephan2796

    stephan2796 20 hours ago

    What do you mean by ''they don't see the bigger picture''. As far as I know, there is no bigger picture. Maths is numbers and rules and nothing else. Now, I can see why you are right, but the explanation that 0.9999....is not 1 makes about as much sense as the explanations of 0.999...=1. Now I don't neccessarily mean you are wrong, but neither do I think you are right. Personally I don't think there is an answer, though I am not a mathematician.

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  • HexagonNiceguy

    HexagonNiceguy 22 hours ago

    Wait! You slapped the owner of numberphile? No need to respond to that. This video proves me wrong about your brain (i thought you were stupid).

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  • zelda12346

    zelda12346 1 day ago

    For the record, you CAN prove something by assuming the thing you're trying to prove. Such a thing is called "proof by induction." The idea is that if the statement works for the first domino, and you can prove that the first domino knocks over the second domino, then all of the dominoes will fall over. That kind of proof isn't what is used in the video or in traditional .9... = 1 proofs, but it's just a point.

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