On 08/12/2008, apptech <apptech@paradise.net.nz> wrote:
> >> A fair number of algebraic calculators use RPN for certain
>  >> functions, such as square root.
>
>  > Oh!  That's an interesting observation.  In fact, popping up my
>  > "scientific calculator" app, I would say that MANY of the functions
>  > beyond basic math are essentially RPN.  (all trig, 10^x, e^x, 1/x, ln,
>  > log, x^2, sqrt(x), factorial.)
>  > Pretty much anything with a single argument.  (this leaves log-base-
>  > y(x) and x^y as about the only ones that aren't, and they're sorta
>  > "mixed")
>
>
>  The "better" algebraic calculators do not use RPN for any functions.
>  And they are an abomination to use. Always IMHO, of course :-).
>
>  If use want sqrt(2) then you press [SQRT] 2
>  That's easy.
>
>  or eg SQRT(X^2+Y^2)
>  Hmm - not sure about X^y and Y^x but maybe
>
>     SQRT(EXP 2 X + EXP 2 Y) =
>
>  FWIW an RPM number manipulation system would do that as
>  e=enter
>
>  2 e X Y e 2 + SQRT
>
>
>                 Russell
>

Russell
Your 2 e X Y e 2 + SQRT doesn't work for me on my trusty old HP11C (&
I can't see how is should work).

X e 2 [y^x] Y e 2 [y^x] + SQRT  does but I'd use :-   X e * Y e * + SQRT

RP
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