# Re: "frac2" button

"IT'S ALL IN THE DOTS"

> I was wondering if there was any program out there that can
> convert a decimal into a true fraction. like say .866025...
> is really the squareroot of 3 over 2. or 1.04719... is really
> pi over 3. i was looking for a "frac2" button.

The decimal 0.866 is not exactly equal to half of the square root of 3,
and it is not reasonable to expect the calculator to tell you that it is.

The decimal 0.866025 is not exactly equal to half of the square root of 3,
and it is not reasonable to expect the calculator to tell you that it is.

The decimal ....    wait a minute!

As soon as you can input a decimal that is _exactly_ equal to half the square
root of 3, then you can start thinking about how to create a "frac2" button
that will report this.  But that will be a very long time!

The best you can possibly do is make a _guess_ or a _bet_ that the decimal
value in your hands was really meant to be an approximation of some particular
easily-described irrational value.  If you have some 12- or 13-place
representation stored in memory W, for example, you might try using >Frac on
W^2 and decide whether you like what you see.  Another plausible effort might
be to divide W by pi (and try >Frac again, maybe).  Of course, what you have
might just be a representation of 2 minus the square root of 3, or the cube
root of 5 plus the cube root of 7, or pi^2, or some weirder number that you
will never guess the secret of.  Calculators are wonderful, but they have no
supernatural powers of divination (as far as I know, anyway).  :-)}

RWW Taylor
National Technical Institute for the Deaf
Rochester Institute of Technology
Rochester NY 14623

>>>> The plural of mongoose begins with p. <<<<

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