Re: TI-M: Algebra
[Prev][Next][Index][Thread]
Re: TI-M: Algebra
> There is a way...here is a basic program that will do the trick...the only
> problem is that its basic and therefore rather slow. It is in ti-86 basic
heh, well, I obviously knew of this but was excluding it because it covers
such a trivial number of cases that it's probably useless. This will only
work if you've got an exact radical. Take sqrt(3)/2, for example - anyone
who's done more than very basic trigonometry knows that's an important
number. Obviously, your routine won't pick up the radical here. Once we
add any constants into the mix, we kill any attempt to ascertain the
irrational number in question.
Furthermore, in a problem somewhat related to what JL mention earlier, how
can you tell an irrational number apart from a rational number with nearly
the same decimal equivalent? It's even worse this time, since there's no
pattern to look for.
Similarly, take Pi or e - not all irration numbers are even related to
radicals (unless, of course, one of these can be expressed in terms of some
radicals in some higher calculus than what I've learned, but I doubt it.
On a side note, I've had my 89 for well over a year and am in precalc, and
I've only used the exact() function _twice_ - and once was just to fool with
it and see if it could pick up equivalents of repeating decimals and
irrational numbers. The other time was on my SAT II Math IIc test last
Saturday, when I realized that I could save a few precious seconds by
letting the calc solve the problem for the approximate decimal answer, then
convert that to the exact number - much faster than having it find the exact
answer for certain complex solve() commands. . .
-Scott
References: