CAS SOLVE uses numeric strategy

th_roch shared this idea 5 years ago
Answered

Dear developers,


using :


SOLVE[x⁵ + x = 2.34]


on Geogebra 5.0.119.0-3D results to


{x = 1.051932190632}.


But this is a numeric solution, not an algebraic!

This is NOT according to the documentation - and might confuse students at school..


I would prefer:

- Either: No result, or

- not an = sign, instead an 'appoximate' sign.

What do you think?


Thank you

Thomas

Comments (5)

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1

Hi,


You posted an inexact (approximate) expression 2.34.


So the answer you get is the appropriate one.


If you want exact solution try the same problem with 234/100.

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1

Sorry, I misread the degree.


In that case there is NO easy solution. You either obtain the one you already received OR


as is the case in many CAS's


a more confusing one as RootOf[x^5 + x - 2.34, X], where X is a number assigned by the system.


Pick and choose.

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1

... thanks for the reply.


A third solution would be writing

    {x≈1.051932190632}

instead of

    {x=1.051932190632}

if a numeric solution is presented.

What do you think?

Thx

Thomas

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1

I see what you mean. I personally do not think it is necessary.


The dot after 1 tells the whole story.

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1

Sorry, we won't be changing this. The current solution is a good, pragmatic compromise

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