Browse Groups

• ... / o o oo o o o o oo o o oo o ooooo / / o o oo o oooo o oo oo o / / o o ooo
Message 1 of 6 , Dec 1 9:37 AM
View Source
gsflom1 wrote:
> Solve to SR precision :
>
> log (base 10) x = (x ^ 2) - 2 .
>

---------------------------------------------------------------
/ o o oo o o o o oo o o oo o ooooo /
/ o o oo o oooo o oo oo o /
/ o o ooo o o ooooo oo ooooo o /
/............................................................../
< o o oo o o oo ooooo o oo <
\ o o o o o o o o \
\ o o o o o \
\ oooo oo ooooooo oooooooo oooooooooo \
\ooooooooooo o oo o oo oo ooo ooooooooooooooo\
---------------------------------------------------------------

Graph the two functions and identify approximate solutions. There are
two solutions: x ~= .01 and x ~= 1.5.

Set cursor to 1.5 on D read L = 0.176, A = 2.25. A is too big so slide
cursor to left until L coincides to fractional part of A. This gets you
to L = .168 A = 2.17 thus D = 1.472.

Observe that .01^2 - 2 is so close to log10(.01) there is no point in
using a slide rule.

Numeric solutions are: 1.472424171, 0.0100230391.

--Mark
• ... The Yahoo Groups mail reader sure mangled that! Let s try again... ... Extra credit for decoding the tape. --Mark [Non-text portions of this message have
Message 1 of 6 , Dec 1 2:13 PM
View Source
--- In sliderule@yahoogroups.com, Mark Armbrust <mark.armbrust@...>
wrote:
>
> [some well mangled ASCII art]

The Yahoo Groups mail reader sure mangled that! Let's try again...

| ---------------------------------------------------------------
| / o o oo o o o o oo o o oo o ooooo /
| / o o oo o oooo o oo oo o /
| / o o ooo o o ooooo oo ooooo o /
| /............................................................../
| < o o oo o o oo ooooo o oo <
| \ o o o o o o o o \
| \ o o o o o \
| \ oooo oo ooooooo oooooooo oooooooooo \
| \ooooooooooo o oo o oo oo ooo ooooooooooooooo\
| ---------------------------------------------------------------

Extra credit for decoding the tape.

--Mark

[Non-text portions of this message have been removed]
• Mark, Nice ascii art! Did you write a program or do this manually? HERE IS ANOTHER OBSOLETE TECHNOLOGY! I decoded manually but halfway through was
Message 1 of 6 , Dec 1 5:27 PM
View Source
Mark,

Nice ascii art! Did you write a program or do this manually?

HERE IS ANOTHER OBSOLETE TECHNOLOGY!<cr>

I decoded manually but halfway through was thinking a program would have
been well worth the effort. :-)

Mike

> --- In sliderule@yahoogroups.com, Mark Armbrust <mark.armbrust@...>
> wrote:
>> [some well mangled ASCII art]
>
> The Yahoo Groups mail reader sure mangled that! Let's try again...
>
> | ---------------------------------------------------------------
> | / o o oo o o o o oo o o oo o ooooo /
> | / o o oo o oooo o oo oo o /
> | / o o ooo o o ooooo oo ooooo o /
> | /............................................................../
> | < o o oo o o oo ooooo o oo <
> | \ o o o o o o o o \
> | \ o o o o o \
> | \ oooo oo ooooooo oooooooo oooooooooo \
> | \ooooooooooo o oo o oo oo ooo ooooooooooooooo\
> | ---------------------------------------------------------------
>
> Extra credit for decoding the tape.
>
> --Mark
• ... I wrote a program to do this a long time ago (timestamp on the source is 5/9/97) and a companion program that does punch cards. I just remembered them
Message 1 of 6 , Dec 1 9:18 PM
View Source
Mike Markowski wrote:
> Mark,
>
> Nice ascii art! Did you write a program or do this manually?
>
> HERE IS ANOTHER OBSOLETE TECHNOLOGY!<cr>
>
> I decoded manually but halfway through was thinking a program would have
> been well worth the effort. :-)
>
> Mike
>

I wrote a program to do this a long time ago (timestamp on the source is
5/9/97) and a companion program that does punch cards. I just
remembered them during the obsolete technology thread.

--Mark
• Very good ! Gary Flom ... From: Mark Armbrust To: sliderule@yahoogroups.com Sent: Saturday, December 01, 2007 12:37 PM Subject: Re: SR Prob : Solve for x ... /
Message 1 of 6 , Dec 1 9:48 PM
View Source
Very good !

Gary Flom

----- Original Message -----
From: Mark Armbrust
To: sliderule@yahoogroups.com
Sent: Saturday, December 01, 2007 12:37 PM
Subject: Re: SR Prob : Solve for x

gsflom1 wrote:
> Solve to SR precision :
>
> log (base 10) x = (x ^ 2) - 2 .
>

----------------------------------------------------------
/ o o oo o o o o oo o o oo o ooooo /
/ o o oo o oooo o oo oo o /
/ o o ooo o o ooooo oo ooooo o /
/............................................................../
< o o oo o o oo ooooo o oo <
\ o o o o o o o o \
\ o o o o o \
\ oooo oo ooooooo oooooooo oooooooooo \
\ooooooooooo o oo o oo oo ooo ooooooooooooooo\
----------------------------------------------------------

Graph the two functions and identify approximate solutions. There are
two solutions: x ~= .01 and x ~= 1.5.

Set cursor to 1.5 on D read L = 0.176, A = 2.25. A is too big so slide
cursor to left until L coincides to fractional part of A. This gets you
to L = .168 A = 2.17 thus D = 1.472.

Observe that .01^2 - 2 is so close to log10(.01) there is no point in
using a slide rule.

Numeric solutions are: 1.472424171, 0.0100230391.

--Mark

[Non-text portions of this message have been removed]
Your message has been successfully submitted and would be delivered to recipients shortly.
• Changes have not been saved
Press OK to abandon changes or Cancel to continue editing
• Your browser is not supported
Kindly note that Groups does not support 7.0 or earlier versions of Internet Explorer. We recommend upgrading to the latest Internet Explorer, Google Chrome, or Firefox. If you are using IE 9 or later, make sure you turn off Compatibility View.