[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: [ATM] Mirror size recommendations?

On Fri, 10 Jun 2005, Mark Holm wrote:

> Oops!  That is what I get for trying to think before I eat.
>
> The REAL shortcut is
> 16 * 16 / (15 * 15)
>
> On most calculators, including the one that comes free with Windows,
> you can do it as:
> 16 <x^2> / 15 <x^2>
>
> In other words, you just take the ratio of the squares of the diameters
> to get the ratio of the areas.  No need to divide by 2 to get the radii,
> or multiply by Pi because those are on both top and bottom and cancel out.

Mine's shorter than yours!

	(16/15)^2

On a RPN calculator that's
	16 15 / X^2

On most algebraics it's
	16 / 15 X^2

I believe that's at its theoretical minimum.

Dave

_______________________________________________
ATM mailing list http://www.atmlist.net/