Re: TI-M: Re: Equation question for TI-89

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Re: TI-M: Re: Equation question for TI-89


Hi,

When I first tried to use the solve( ) function, I used it with the "and" logic
operator as you initially stated and it did not work.  (I didn't however mention
that before).  I just tried it again, and it worked perfectly. Which leads me to
believe that I simply made an error inputting it the first time. Probably a
spacing error around the "and" operator.

At any rate, Mike, I just wanted to clear up that I never had any doubt in you
or your advice; instead it was completely the opposite. The whole time, I was
trying to make clear that I didn't know what I was doing and all mistakes if any
were on my part.
Thanks for your patience and all of your help.

Bobbyjoe Glover


Mike Grass wrote:

> BG,
>
> "and" goes in place of "and"  I showed exactly how it would be inputted on
> the command line (with spaces added between operators for an easier read on
> the computer):
>
> solve(-1 = -1a + 3b and 3 = 2a-5b, {a,b})
>
> Just enter it in exactly as shown (well, without the spaces before and after
> operators). Yes {a,b} should have the curly brackets around it, because it
> is a _list_ of all variables you want to solve for.
>
> >From: BG <gloverbo@msu.edu>
> >Reply-To: ti-math@lists.ticalc.org
> >To: ti-math@lists.ticalc.org
> >Subject: Re: TI-M: Re: Equation question for TI-89
> >Date: Fri, 15 Sep 2000 13:32:20 -0400
> >
> >
> >Mike,
> >
> >Thank you for explaining that to me.
> >I used the rref( ) function you suggested and found it works perfectly for
> >my
> >needs. Thanks a lot!
> >
> >But for the solve( ) function I keep getting a syntax error ("too many
> >arguments"); I'm not exactly sure how to enter it using the solve function.
> >I
> >believe I am doing something wrong.
> >"solve(-1 = -1a + 3b and 3 = 2a-5b, {a,b})"
> >where the word 'and' is, what should I use?  a "," or perhaps a ";"?  Also,
> >do I literally put the brackets around a and b "{a,b}" ?
> >
> >At any rate, thanks a lot for the help. I can now use the rref for any of
> >my
> >needs. I guess my curiosity in the solve function is just academic at this
> >point. Thanks!
> >
> >BG
> >
> >Mike Grass wrote:
> >
> > > You can always look up the manual at TI's web site....
> > >
> > > The 89/92+ have a great built-in linear systems of equation solver, just
> > > enter
> > >
> > > solve(eqw1 and eqw2, {varlist})
> > >
> > > Using your example, you would type
> > >
> > > solve(-1 = -1a + 3b and 3 = 2a-5b, {a,b})
> > >
> > > which returns
> > >
> > > a=4 and b=1
> > >
> > > If you want to do it with matrices, you can use rref(--which finds the
> > > reduced row echelon form--on the standard augmented matrix:
> > >
> > > rref( [[-1,3,-1] [2,-5,3]] )
> > >
> > > which returns
> > >
> > > [[1 0 4]
> > >  [0 1 1]]
> > >
> > > --Mike
> > > ----- Original Message -----
> > > From: "BG" <gloverbo@msu.edu>
> > > To: <ti-math@lists.ticalc.org>
> > > Sent: Thursday, September 14, 2000 10:38 PM
> > > Subject: TI-M: Equation question for TI-89
> > >
> > > >
> > > > Hi everybody,
> > > >
> > > > I'm new to this list. I have a question that probably has an easy
> > > > answer.
> > > > I am about 50 miles away from my TI-89's manual, so unfortunately I
> > > > can't find my answer there.
> > > >
> > > > PROBLEM:  how can I enter a system of equations into my TI-89 and have
> > > > it solve them?
> > > > For instance:
> > > >
> > > > -1 = -1A + 3B
> > > > 3 = 2A - 5B
> > > >
> > > > What do A & B equal?
> > > >
> > > > This is two equations with 2 unknowns. Isn't there a function to solve
> > > > this? Can't I do this with a Matrix?  If so, could somebody please
> >tell
> > > > me how to do it on a TI-89?  I'm going to need to be able to do it
> >with
> > > > 3 equations and 3 unkowns, also. I have an old Casio that I can do it
> > > > on, but my 89 is a great calculator and I'd like to use it for all my
> > > > needs.
> > > >
> > > > Thanks!
> > > >
> > > > B. G.
> > > >
> > > >
> > > >
> >
> >
>
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