Re: Program Request
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Re: Program Request
n X t wrote:
>
> On Fri, 17 Oct 1997 15:07:12 -0700 (PDT) Sumit <sumit-1@rocketmail.com>
> writes:
> >But TI-83 solver cannot solve linear equations. I am talking about
> >the linear equations.
>
> use the stat function.. and list.. and solve it using LinR..
>
> and Linear you mean Y=mX+b right?? if it is.. just do it by hand..
I'm sorry I'm a bit late for this discussion, but:
Are you kidding? What did you buy your calc for? Still doing math by
hand?
For solving multiple linear equations you should proceed like this:
If your problem looks like a11*x + a12*y + a13*z = b1
a21*x + a22*y + a23*z = b2
a31*x + a32*y + a33*z = b3
(a11 a12 a13) (b1)
then you enter two matrices: a = (a21 a22 a23) b=(b2)
(a31 a32 a33) (b3)
(x)
the result vector is r=(y) (don't type it in!)
(z)
Now, following linear algebra: since a * r = b (that's the original
question), you have also r = inverse(a) * b.
What you do is simply invert the matrix a - try something like a^-1, and
then multiply it by the b vector. I know the TI-81 can do this, and
every better one I've seen up to now.
If the calc complains about inverting the a matrix, then your equation
system doesn't have an unique solution but rather a whole infinity of
them - bad luck.
In short form: a^(-1)*b->r
For bigger equation systems this works the same way.
Greetings, -R.
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