• Kairos
    link
    fedilink
    English
    441 year ago

    0.9<overbar.> is literally equal to 1

    • @UnderpantsWeevil@lemmy.world
      link
      fedilink
      English
      191 year 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
      • Kairos
        link
        fedilink
        English
        81 year ago

        Even simpler: 1 = 3 * 1/3

        1/3 =0.333333…

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

      • @Swedneck@discuss.tchncs.de
        link
        fedilink
        English
        31 year 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
          link
          fedilink
          English
          21 year 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.