• Kairos
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    436 days ago

    0.9<overbar.> is literally equal to 1

    • @UnderpantsWeevil@lemmy.world
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      196 days ago

      There’s a Real Analysis proof for it and everything.

      Basically boils down to

      • If 0.(9) != 1 then there must be some value between 0.(9) and 1.
      • We know such a number cannot exist, because for any given discrete value (say 0.999…9) there is a number (0.999…99) that is between that discrete value and 0.(9)
      • Therefore, no value exists between 0.(9) and 1.
      • So 0.(9) = 1
      • @Swedneck@discuss.tchncs.de
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        33 days ago

        the explanation (not proof tbf) that actually satisfies my brain is that we’re dealing with infinite repeating digits here, which is what allows something that on the surface doesn’t make sense to actually be true.

        • @UnderpantsWeevil@lemmy.world
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          23 days ago

          Infinite repeating digits produce what is understood as a Limit. And Limits are fundamental to proof-based mathematics, when your goal is to demonstrate an infinite sum or series has a finite total.

      • Kairos
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        86 days ago

        Even simpler: 1 = 3 * 1/3

        1/3 =0.333333…

        1/3 + 1/3 + 1/3 = 0.99999999… = 1