# HP Forums

Full Version: WP 34S mini-challenge (B)
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

Write a WP 34S program that displays (and keeps displaying) at least the first 10 correct digits of Brun's Constant, B = 1.902160583104 (the last two digits are uncertain). The maximum number of steps is 10, plus one for each additional digit, up to 12 steps (LBL and END included).

Tip: the following approximation may be used:

```B ~ Sqrt(Phi*Sqrt(5.0005)) = 1.90216058363
```
where
```Phi = (sqrt(5) + 1)/2
```
I have only a 10-step solution:
```001 LBL B
002
003
004
005
006
007
008
009
010 END
B  -->  1.90216058363
```
Gerson.

Edited: 27 Dec 2012, 12:09 a.m.

Saved one step immediately:

```001: LBL B
002: 5
003: SDR 004
004: RCL+ L
005: [sqrt]
006: # [phi]
007: [times]
008: [sqrt]
009: RTN
```

Pauli

Quote:
004: RCL+ L

D'oh, missed this obvious one!

Gerson.

And adding a correction term takes three more steps, giving 12 digits on the display although the last is off by a bit:

```001: LBL B
002: 5
003: SDR 004
004: RCL+ L
005: [sqrt]
006: # [phi]
007: [times]
008: [sqrt]
009: # 53
010: SDR 11
011: -
012: RTN
```

- Pauli

10 actual steps for 11 correct digits... this is really compact. #52 instead of #53 might be better.

Gerson.

I didn't fiddle with the correction factor, just interested in the displayed value. Pity the correction value is >255 or an extra digit would have been available for free.

I wouldn't be surprised if a shorter sequence were still possible.

- Pauli

This Message was deleted. This empty message preserves the threading when a post with followup(s) is deleted. If all followups have been removed, the original poster may delete this post again to make this placeholder disappear.

Another approach, it gets thirteen digits in 12 working steps.

```001: LBL B
002: # 216
003: SDR 005
004: #058
005: SDR 008
006: #031
007: SDR 10
008: 4
009: SDR 12
010: [cmplx]+
011: +
012: # 019
013: SDR 001
014: +
015: RTN
```

- Pauli

Edited: 27 Dec 2012, 1:02 a.m.

Quote:

Is there anything B is good for beyond pure math?

d:-)

What does it matter? More is always better!

- Pauli

Quote:
What does it matter?
Thanks, that suffices as response - now I know ;-)
Quote:
More is always better!

So you prefer 8.5 over 5.8 on the Richter scale?

([:-)

This Message was deleted. This empty message preserves the threading when a post with followup(s) is deleted. If all followups have been removed, the original poster may delete this post again to make this placeholder disappear.

Quote:
Well, in 1994 it played an important role in the discovery of the famous Pentium FDIV flaw:

That's of course a serious reason to include it in the WP34s. ;-)

Go on Pauli ... :-)

Franz

Oh yes - we won't take any lower grade challenges, will we? ;-)

Thank you very much for you interest, Paul.

I am sorry if I may have offended someone else's intelligence by posing a "lower grade challenge". Anyway, this was meant to be a simple mini-challenge.

Gerson

Oooh, Gerson, you may have got my message wrong :-? I was just referring to Franz' post and meant we won't introduce a mathematical constant for less reasons than unvealing Intel.

d:-)

I thought the challenge was interesting and I'd still be surprised if a better/shorter solution didn't exist. At the very least it helped take my mind off of the pain of my recent tonsillectomy for a while which was a significant benefit personally.

- Pauli

I hope you'll recover soon.