• rasensprenger@feddit.de
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    8 months ago

    About the ambiguity: If I write f^{-1}(x), without context, you have literally no way of knowing whether I am talking about a multiplicative or a functional inverse, which means that it is ambiguous. It’s correct notation in both cases, used since forever, but you need to explicitly disambiguate if you want to use it.

    I hope this helps you more than the stackexchange post?

    • 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱
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      8 months ago

      If I write f^{-1}(x), without context, you have literally no way of knowing whether I am talking about a multiplicative or a functional inverse, which means that it is ambiguous

      The inverse of the function is f(x)^-1. i.e. the negative exponent applies to the whole function, not just the x (since f(x) is a single term).

      • rasensprenger@feddit.de
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        8 months ago

        You can define your notation that way if youlike to, doesn’t change the fact that commonly f^{-1}(x) is and has been used that way forever.

        If I read this somewhere, without knowing the conventions the author uses, it’s ambiguous

        • 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱
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          8 months ago

          You can define your notation that way if you like

          Nothing to do with me - it’s in Maths textbooks.

          without knowing the conventions the author uses, it’s ambiguous

          Well they should all be following the rules of Maths, without needing to have that stated.

              • rasensprenger@feddit.de
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                8 months ago

                Yeah, doesn’t mean that you know what an author is talking about when you encounter it doing actual math

                The notation is not intrinsically clear, as any human writing. Ambiguous, one may say.

                  • rasensprenger@feddit.de
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                    8 months ago

                    We’ve been at this point, I’m not going to explain this again. But you weren’t able to read a single sentence of a wikipedia article without me handfeeding it to you, so I guess I shouldn’t be surprised. I’m sorry for your students.