Velocity Reviews > Perl > Looking for Equation Solver

# Looking for Equation Solver

Chris
Guest
Posts: n/a

 09-03-2005
Hi,

does anybody know a Perl program or script that is able to solve
mathematical equations. So, if I input a string, say, \$e = "2x+1=5";
the output would be "x=2".

If anybody knows about a program that can do something like this, please
let me know.

Thank you,
Chris

Ignoramus14363
Guest
Posts: n/a

 09-03-2005
I wrote one

http://www.algebra.com/services/rend...simplifier.mpl

Besides simplifying, it shows work and plots math formulas. It is not
available publicly though. There is a Math::Symbolic module, but I
found it extremely lacking.

i

On Sat, 03 Sep 2005 19:49:43 +0200, Chris <no@spam> wrote:
> Hi,
>
> does anybody know a Perl program or script that is able to solve
> mathematical equations. So, if I input a string, say, \$e = "2x+1=5";
> the output would be "x=2".
>
> If anybody knows about a program that can do something like this, please
> let me know.
>
> Thank you,
> Chris

--

xhoster@gmail.com
Guest
Posts: n/a

 09-03-2005
Ignoramus14363 <ignoramus14363@NOSPAM.14363.invalid> wrote:
> I wrote one
>
> http://www.algebra.com/services/rend...simplifier.mpl
>
> Besides simplifying, it shows work and plots math formulas. It is not
> available publicly though.

Also, it doesn't give the right answer.

"Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
(x-3)/(x+2)"

No, it doesn't.

Xho

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Ignoramus14363
Guest
Posts: n/a

 09-03-2005

On 03 Sep 2005 22:51:13 GMT, http://www.velocityreviews.com/forums/(E-Mail Removed) <(E-Mail Removed)> wrote:
> Ignoramus14363 <ignoramus14363@NOSPAM.14363.invalid> wrote:
>> I wrote one
>>
>> http://www.algebra.com/services/rend...simplifier.mpl
>>
>> Besides simplifying, it shows work and plots math formulas. It is not
>> available publicly though.

>
> Also, it doesn't give the right answer.
>
> "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
> (x-3)/(x+2)"
>
> No, it doesn't.

I will appreciate corrections and suggestions. What's the right answer
there?

i

Keith Keller
Guest
Posts: n/a

 09-04-2005
On 2005-09-03, Ignoramus14363 <ignoramus14363@NOSPAM.14363.invalid> wrote:
>
> On 03 Sep 2005 22:51:13 GMT, (E-Mail Removed) <(E-Mail Removed)> wrote:
>>
>> Also, it doesn't give the right answer.
>>
>> "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
>> (x-3)/(x+2)"
>>
>> No, it doesn't.

>
> I will appreciate corrections and suggestions. What's the right answer
> there?

If you can't figure it out on paper, why are you writing a program to do
it? Sheesh, I might as well go write an OS! :-\

--keith

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Ignoramus14363
Guest
Posts: n/a

 09-04-2005
On Sat, 3 Sep 2005 22:47:50 -0700, Keith Keller <(E-Mail Removed)-francisco.ca.us> wrote:
> On 2005-09-03, Ignoramus14363 <ignoramus14363@NOSPAM.14363.invalid> wrote:
>>
>> On 03 Sep 2005 22:51:13 GMT, (E-Mail Removed) <(E-Mail Removed)> wrote:
>>>
>>> Also, it doesn't give the right answer.
>>>
>>> "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
>>> (x-3)/(x+2)"
>>>
>>> No, it doesn't.

>>
>> I will appreciate corrections and suggestions. What's the right answer
>> there?

>
> If you can't figure it out on paper, why are you writing a program to do
> it? Sheesh, I might as well go write an OS! :-\

Let me know when you have something useful and substantial to say,
okay?

(hint, I did solve it on paper)

If you can explain why the above simplification is incorrect, I would
appreciate hearing that.

i

BZ
Guest
Posts: n/a

 09-04-2005
Ignoramus14363 wrote in comp.lang.perl.misc:
> > "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
> > (x-3)/(x+2)"
> > No, it doesn't.

>
> I will appreciate corrections and suggestions. What's the right answer
> there?

(x-3)^2/(x-4)^2

--
BZ

Paul Lalli
Guest
Posts: n/a

 09-04-2005
Ignoramus14363 wrote:
> Keith Keller wrote:
> > Ignoramus14363 wrote:
> >> (E-Mail Removed) wrote:
> >>>
> >>> Also, it doesn't give the right answer.
> >>>
> >>> "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15)) simplifies to
> >>> (x-3)/(x+2)"
> >>>
> >>> No, it doesn't.
> >>

> If you can explain why the above simplification is incorrect, I would
> appreciate hearing that.
>

Uhm. Because it's not mathematically valid? Try any value of X. The
original does not produce the same result as the simplification. (Hint
- the easiest value to plug in would be 0, which gives -3/2 for the
simplification, but
(-9/10) / (6/15) = (-9/10) * (15/6) = (-3/2) * (3/2) = -9/4 for the
original).

fwiw, when I do it on paper I get:
(x^2 - 6x - 9) / (x^2 -4)

(Granted, it has been about 5 years since I last took a math class...)

Paul Lalli

Dave
Guest
Posts: n/a

 09-04-2005

"BZ" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Ignoramus14363 wrote in comp.lang.perl.misc:
>> > "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15))
>> > simplifies to
>> > (x-3)/(x+2)"
>> > No, it doesn't.

>>
>> I will appreciate corrections and suggestions. What's the right answer
>> there?

>
> (x-3)^2/(x-4)^2
>
> --
> BZ

No, Paul is right. It can also be written:
((x-3)^2)/((x+2)(x-2))
or
(x-3)^2/(x^2-4)
the latter of which is perhaps what BZ meant to type.

Dave
Guest
Posts: n/a

 09-04-2005

"Ignoramus14363" <ignoramus14363@NOSPAM.14363.invalid> wrote in message
news:bdwSe.98947\$(E-Mail Removed).. .
> On Sat, 3 Sep 2005 22:47:50 -0700, Keith Keller
> <(E-Mail Removed)-francisco.ca.us> wrote:
>> On 2005-09-03, Ignoramus14363 <ignoramus14363@NOSPAM.14363.invalid>
>> wrote:
>>>
>>> On 03 Sep 2005 22:51:13 GMT, (E-Mail Removed) <(E-Mail Removed)>
>>> wrote:
>>>>
>>>> Also, it doesn't give the right answer.
>>>>
>>>> "Text form: ((x^2-6x+9)/(x^2-3x-10))/((x^2-5x+6)/(x^2-8x+15))
>>>> simplifies to
>>>> (x-3)/(x+2)"
>>>>
>>>> No, it doesn't.
>>>
>>> I will appreciate corrections and suggestions. What's the right answer
>>> there?

>>
>> If you can't figure it out on paper, why are you writing a program to do
>> it? Sheesh, I might as well go write an OS! :-\

>
> Let me know when you have something useful and substantial to say,
> okay?
>
> (hint, I did solve it on paper)
>
> If you can explain why the above simplification is incorrect, I would
> appreciate hearing that.
>
> i
>

The error in the explanation this example is at the line:
'Canceled out common factors (x-(3)),(x-(3))'

Where (1) is left in each case instead of (x-3) and (x-2) in numerator and
denominator respectively.

The explantion would be clearer if you showed the factorisation before the
cancellation, and this error would have been more obvious too.

Hope this helps

Dave