Re: TI-M: TI-89 root question


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Re: TI-M: TI-89 root question




On the TI calculators while x^n has highest prescedence.  x^a^b^c^d... etc
sequece is evaluated left to right. The  HP48X does the same for algebraic
evaluation.

At the TI web site it is recommend that such should be put in parenthesis.
So 4^2^3 should be witten as (4^2)^3 or 4^(2^3) if that is how you want it
evaluated.

Also  the TI-82, TI-85 will evaluate  a  10/2A, A being equal to 3, as
1.666....  Where as the TI-83, TI-83+, TI-86, TI-92, TI-92+, TI_89 as 15.

The TI-82, TI-85 parsed as one might write an implied multipication in a
division. The other TI's interpret 10/2A the same as 10/2*A.

TI recommens the use of the parenthesis to avoid ambiguity.


----- Original Message -----
From: "Scott Noveck" <noveck@pluto.njcc.com>
To: <ti-math@lists.ticalc.org>
Sent: Wednesday, June 07, 2000 8:49 PM
Subject: Re: TI-M: TI-89 root question


>
> > a^(1/n) =
> > a^(n^(-1)) = a^n^(-1) because ^ is highest prescedence and right
> > associative...(at least in standard arithmetic parsers, but I believe
the
> > TI-89 follows this convention too)
>
> Don't use that last form (a^n^-1) on the calcs.  There's a supposedly a
bug
> in most ROM versions of most z80 calcs where the precedence of powers to
> powers is not evaluated correctly, and that may be taken as (a^n)^-1
rather
> than a^(n^-1).
>
> I'm not sure exactly which calcs this affects, but I remember HP listing
the
> HP49G's correct evaluation of this as a "feature" in which they claimed
that
> the HP48 line and all ti graphing calcs except the 89, 92(+), and I
believe
> 86 (one of the z80 calcs) all suffer from this incorrect evaluation.  I've
> got easy access to a friends' 82/83/83+/85/86 calcs in school, so maybe
I'll
> test it out tomorrow and post the results here.
>
>     -Scott
>
>
>




References: