Re: Various notes about the TI 92
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Richard Gallagher wrote:
>
> These are just a few things I have noticed about the TI-92 and
> suggestions about what could be changed.
I find most of your complaints unwarranted. It seems to me that the
TI-92 isn't the problem, you are.
> It needs support for different number bases, I have to keep my TI-85
> handy incase I need to use binary or hex.
Program available to convert from different bases.
> I find it annoying how it moves square roots from the bottom to the
> top. e.g. the one over the square root of 2 becomes the square root
> of 2 divide by 2. It would be nice if this feature could be turned
> off.
The TI-92 is just doing what it's supposed to: simplify radicals.
> The TI-92 gives a incorrect result for the limit of 0^x as x tends
> toward 0. It gives the limit as 1 from the left, right and both
> sides. In fact the limit is 0 from the right, no limit from the left
> and hence no limit from both sides. It does give a 0^0 replaced by 1
> warning, but that does not really make up for it.
Judging the performance of a calculator on such a trivial problem as
lim 0^x is stupid.
> Another feature that is missing from the TI-92 was the physical units
> converter. I know there is a program available for the 92 that will
> do this but it is a bit limited e.g. you can't use the program in
> conjunction with the solver to find what temperature has the same
> value in both celsius and fahrenheit. You could do that on the TI-85.
I think the program works fine.
> Another thing I miss is physical constants! It is of course easy to
> add them in but it would be nice if they were built in. They could be
> implemented like pi and e are in exact mode.
TI cannot guess what constants you will need. They feel it is easier
for you to make your own.
> One small thing that would be nice is if the complex number symbol 'i'
> could be changed to a 'j' at will. It is only a little thing, but AC
> electronics is hard enough with out having to convert j's to i's them
> i's to j's.
i stored to j. Problem solved.
> Something I have noticed with polynomials and the Sigma (sum) is that
> if you do it in a round about way it is faster than doing it directly.
> e.g.
> it is faster to do (capital E represents sigma)
> E(x^2+3x+4,x,1,b)
> which gives b^3/3+2b^2+17b/3
> then substitute in a value for 'b' and you get the answer.
> For large b (>200) this is often quicker than entering 'b' directly
> E(x^2+3x+4,x,1,100000) takes a long time, doing the above takes a lot
> shorter time.
>
> Richard Gallagher
> rwg1@wave.co.nz
Finding the sum the second way takes longer because by using a number
instead of a variable for the summed to value, you force the calc to
actually add up all of the terms from 1 to 100000. However, on more
complex series, the TI-92 cannot find a general term for the sum of the
first b terms, so you must resort to the second method.
<pre>
--
Mike Harder
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