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Re: MathML 2.0 Last call
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<blockquote TYPE=CITE>Janet Daly wrote:
<p> > This is the Last Call Working draft and the review period
<br> > ends 30 April.
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My short comment is about the names of the inverse hyperbolic functions
in MathML 2.0. The inverse trigonometric functions have prefix "arc"
<blockquote><tt>sin -> arcsin, cos -> arccos, ...</tt></blockquote>
The reason is that they return the angle (measured by arc on unit sphere).
That interpretation is not valid for hyperbolic functions. Their inverses
are (historically) related to area. Therefore the prefix for inverse hyperbolic
functions is "ar" (not "arc"):
<blockquote><tt>sinh -> arsinh, cosh -> arcosh, ...</tt></blockquote>
<tt>or</tt>
<blockquote><tt>sh -> arsh, ch -> arch, ...</tt></blockquote>
One can double check it with reputable sources such as the
famous "Handbook of Mathematical Functions" by M. Abramowitz and I. Stegun.
<p>Regrettably, the incorrect naming somehow got its way to software engineering
(for instance Mathematica uses ArcSinh, ArcCosh, etc.) and it is
spreading. I have already seen some math books using it. I suggest the
return to traditional, correct, and meaningful names for inverse hyperbolic
functions before it is to late.:-)
<p>-- Leszek Sczaniecki
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