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Full Version: (O.T.) Happy 'XROOT(9,10561572*EXP(2))/sqrtLN(pi)' ! (N.T.)
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HAPPY 4TH OF JULY!

... correct to 10 digits ! ... :-)

Best regards from V.

Hi Valentin,

7.042009002 on the 15C and 7.04200900084 on the 33s.

Yes, I know your HP-71B IDENTIFY. Should have used it. Anyway, I spent no more than 5 minutes doing it by hand on the 33s. By the way, I tried 7.04000000001 on Plouffe's inverter but it wouldn't find anything closer...

Best regards,

Gerson.

----

P.S.: Another one just worked out to celebrate the 30th birthday of the HP-41C:

'(45/2+1/47075)/pi' => 7.1619792009


Edited: 5 July 2009, 1:27 p.m.

Not that it is of any relevance to where I live of course, but how about these two gems:

4 SIN e^x ->H.MS 6 +
4 LN 3 3 / 7 +

The first is good in degrees mode on many/most scientific models. The second works on a 12c and is only one operation longer.
Both need FIX 6 set.


- Pauli

Getting them in just a few steps is very hard. I would guess you have written a special software to find them... If such is the case, it is interesting just the same.

Twice as much steps on the 12c but relevant to where I live:

EEX 2 12x ENTER 7 e^x EEX 3 / LN - LN

It works with the 12c default FIX 2 (but would work up to FIX 7).
Our national date in our date format, DD.MM... :-)

Regards,

Gerson.

P.S.: Not so exact but works with FIX 2 and takes the same number of steps it would need to just writing the date:

EEX 2 12x LN

Edited: 5 July 2009, 8:27 p.m.

Quote:
I would guess you have written a special software to find them... If such is the case, it is interesting just the same.

Yes, I do have a little helper program that simplifies searching for these :) It started off just applying a set of functions to a value and printing the nearer misses. Later, it grew to allow several function applications. Now it is closer to a mini-rpn calculator that does a real search. My goal is to ultimately have it do an automatic search.

I've been meaning to finish it and clean it up so I can post it online for one and all to use. When I get some time and motivation...

- Pauli

Quote:
I've been meaning to finish it and clean it up so I can post it online for one and all to use.

Looking forward to it! Quite useful when one wishes to save some steps when entering constants in programs. For other applications, Inverse Symbolic Calculator might be an option. It correctly identifies 7.04200892003 as '7+2/33*LN(2)' but doesn't simplify it (Advanced lookup). However it fails for 7.04200900084: it just returns "Wow, really found nothing." That'll require Valentin's HP-71B program (Datafile V26N2P24, March/April 2007).

Regards,

Gerson.

Hi, Gerson:

    Gerson posted:

      "However it fails for 7.04200900084: it just
      returns "Wow, really found nothing." That'll require Valentin's HP-71B program (Datafile V26N2P24, March/April 2007)."

    If using the European date format instead of the US one, i.e., 4.072009, my HP-71B IDENTIFY program provides:

    which is correct to 11 digits.

Best regards from V.