Is the Notation for Inverse Functions Ambiguous?

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Discussion Overview

The discussion revolves around the notation for inverse functions, particularly the debate between using pi (π) and tau (τ) in mathematical contexts. Participants explore the implications of these notations on mathematical intuition, historical significance, and practical applications in geometry and trigonometry.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants express discomfort with the historical use of pi, suggesting that tau could provide clearer geometric intuition, especially in relation to the unit circle.
  • Others argue that the current definition of pi is historically significant and that the benefits of switching to tau do not outweigh the established conventions.
  • A few participants share humorous anecdotes related to teaching and learning mathematics, highlighting the challenges and absurdities encountered in academic settings.
  • There is a suggestion that the radius is a more fundamental unit than the diameter, which could support the argument for using tau instead of pi.
  • Some participants question the practicality of measuring radius versus diameter in real-world applications, suggesting that this should not influence mathematical definitions.
  • Concerns are raised about the potential confusion that could arise from changing established notations, with some participants advocating for maintaining the current system.

Areas of Agreement / Disagreement

Participants generally do not reach a consensus on the use of pi versus tau. Multiple competing views remain regarding the clarity, historical significance, and practicality of each notation.

Contextual Notes

Some arguments depend on subjective interpretations of clarity and intuition in mathematics, and there are unresolved questions about the implications of changing established mathematical constants.

  • #31
micromass said:
Just imagine that advanced civilizations in space have missed us because we've been sending pi into space, and not tau :biggrin:

Well, they wouldn't have been so advanced to not recognize we were sending \tau/2.
 
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  • #32
Especially if we send in binary, you'd really have to be an idiot not to recognize it.
 
  • #33
HallsofIvy said:
Of course, the reason the Greek's chose to give a symbol for \pi rather than 2\pi is that the cirumference of a circle is 2\pi r or \pi d and it is much easier to measure the diameter of a log than the radius.
Since when are logs circular? :-p
 
  • #34
TylerH said:
Since when are logs circular? :-p

By right about the same time cows became spherical.
 
  • #35
Dickfore said:
By right about the same time cows became spherical.

Wait...cows aren't really spherical?
 
  • #36
Theoretically...
 
  • #37
jhae2.718 said:
Wait...cows aren't really spherical?

Just in case you haven't been aware:

http://en.wikipedia.org/wiki/Spherical_cow"
 
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  • #38
micromass said:
Well I certainly consider pi to be an unfortunate historic mistake. Math would be slightly more beautiful with tau. But this is the way it is and we need to stick with it.

Other unfortunate mistakes are the definition of the gamma function and the notation \subset to mean subset or equal. But there's nothing we can do about those now...

Yes. Notations like sin^-1 are a bit ambiguous quite often.
 
  • #39
dimension10 said:
Yes. Notations like sin^-1 are a bit ambiguous quite often.

IMHO, it's the notation sin^n(x)=\left( sin(x) \right)^n that is ambiguous, rather than inverse notation. In general, f^{-1} is ubiquitously the inverse of f.
 

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