• nyan@lemmy.cafe
    link
    fedilink
    English
    arrow-up
    7
    arrow-down
    1
    ·
    14 hours ago

    x-¹

    Where I come from, that’s read as “x to the [power of] minus one”. “x minus one” is, well, x - 1. Not the same thing at all.

    (I admit, my chances of deciphering what you meant might not have been all that high even if you’d used the correct phrasing, but without it, the chance was zero.)

    • Miller@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      arrow-down
      5
      ·
      14 hours ago

      It was a shorthand he used, he wrote it as a superscript, it must of been his own, it was useful in terms of statistics analysis. Don’t worry too much about your ability to decipher things, from your mathematical explanation I imagine it’s something you have had to carry all of your life.

      • SCmSTR@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        5
        ·
        13 hours ago

        It has been a LONG time since I did any real math and never took statistics, but wouldn’t x^(-1) just be 1/(x)? I don’t know if that equates to “everything that isn’t x”. I feel like there’s a specific way to write that, but a negative exponent is not that, I don’t think, but also I have no idea.

        I looked it up. Looks like this stuff is maybe from set theory? Which I sooorrrrt of remember doing at some point?

        My best guess is your professor either said something from this, or you misremembered, or I’m totally off base and I’m still curious.

        https://en.wikipedia.org/wiki/Complement_(set_theory)

        • Miller@lemmy.world
          link
          fedilink
          English
          arrow-up
          2
          arrow-down
          1
          ·
          12 hours ago

          Your best guess is reasonable, I may have misremembered, it could have been A’ spoken as A dash and meaning the complement and I hallucinated the negative but I think I recall some noted confusion with the reciprocal x-¹ = 1/x.

      • nyan@lemmy.cafe
        link
        fedilink
        English
        arrow-up
        3
        arrow-down
        1
        ·
        13 hours ago

        We may also be separated by a common llanguage—“lecturer” isn’t a word that’s much used in Canada. I’ve only encountered it as a Briticism.

        • Miller@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          2
          ·
          12 hours ago

          I read your reply as snarky but I think it may have been just differences in phrasing.