Modern Electronics (was Re: List charter mods & headcount... ;

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Jun 23 17:19:45 2004

> In my day, we were to supply our own scratch paper for standardized tests,
> including graph paper. We were not allowed to bring in sliderules,
> but there was no rule against making one during the test!

When I did O-level maths <mumble> years ago, we couldn't use a calculator
or slide rule for one of the papers. But we were allowed to take in a
ruler. I asked if I could take in _2_ rulers. They said 'sure'. I then
showed said teacher how to use 2 rulers to make an adding device (a slide
rule with linear scales, of course). The look on the teacher's face was
priceless.

> How many current students can find a square root without a sqrt or x^y key
> on a calculator?

I've had many an argument with my father over this. He insists on using
the binomial expansion. I prefer the Newton iteration, which converges
very quickly

[ To find sqrt(A)

Set X(0) = A/2 (or some other suitable initial guess)
Repeat
  X(N+1) = ( (A/X(N)) + X(N) ) / 2
Unti X(N) and X(N+1) are sufficiently close
Return X(N+1)

]



>
> How many even know the square root of 2 and 3?

_Nobodu_ knows those values, since they're irrational. 1.4142 and 1.732
seem to be useable approximations (in decimal!) for most work :-)

>
> I even get some who have been TAUGHT that pi is EXACTLY 22/7.

Eeek!. I prefer 355/113, but I do know that's an approximation.

> > industry on the surface of things think they want. I do wonder quite
> > where things will be in ten years when there's almost nobody left who
> > can actually think for themselves though...

I hope to still be alive in 10 years time (unless I connect myself
accidentally to the wrong points in an SMPSU or something !), and I hope
to still be thinking.

-tony
Received on Wed Jun 23 2004 - 17:19:45 BST