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Werner_E25-Diamond I
25-Diamond I
November 30, 2021
Question

Bug in Symbolic Solver

  • November 30, 2021
  • 2 replies
  • 7632 views

This thread was broken off of this original topic thread.  

 

BTW, does anyone know, why Primes symbolic can't solve this simple system of equations?

The new symbolic in Prime 6 claims that no solution was found and the legacy one (muPad) runs quite long and then we see

Werner_E_1-1638282624189.png

A similar useless result in MC15 which uses MuPad, too.

The system can be easily solved by hand and we get

Werner_E_3-1638282726349.png

Guess MC11 with Maple under the hood for symbolic does not show that problem of not being able to solve this system.

 

 

 

    2 replies

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    LucMeekes23-Emerald IV
    23-Emerald IV
    November 30, 2021

    Challenge accepted, Mathcad 11/Maple finds an exact solution:

    LucMeekes_1-1638284552852.png

    And if you want the numerical results:

    LucMeekes_2-1638284581214.png

     

    Success!
    Luc

     

      W
      Werner_E25-Diamond IAuthor
      25-Diamond I
      November 30, 2021

      I didn't doubt that MC11 would be able to solve the system.

      The interesting part is that MC15 can do likewise!

      Its only until you feed numbers in first place that the system can't be solved:

      Werner_E_0-1638294029871.png

      How does MC11 handle this?

       

      L
      LucMeekes23-Emerald IV
      23-Emerald IV
      November 30, 2021

      That's in line with my philosophy:

      If you want to work symbolically, then use symbols as much as possible. Once you have a symbolic solution you can fill in numbers, to get a numeric answer.

       

      As a matter of fact, I didn't even try to use the numbers with the symbolics, until now:

      LucMeekes_0-1638298825047.png

      The error message is "Unknown error"... 😶

       

      Success!
      Luc

        S
        StuartBruff23-Emerald V
        23-Emerald V
        November 30, 2021

        Did you mean to post this observation here, Werner?   It seems like it should be a thread in its own right ... 🤔

         

        Stuart

        W
        Werner_E25-Diamond IAuthor
        25-Diamond I
        November 30, 2021

        I came up with this while creating the dummy function for my answer.
        But of course you are right thats it off-topic.

         

        EDIT: Now, since the original thread was splitted, its perfectly on-topic 🙂

        S
        StuartBruff23-Emerald V
        23-Emerald V
        November 30, 2021
        @Werner_E wrote:

        I came up with this while creating the dummy function for my answer.
        But of course you are right thats it off-topic.

        I was trying, unsuccessfully, to hint that it seems sufficiently worthwhile to ask a kindly (or grumpy) Moderator to split it off and delete the extraneous messages (such as mine!).  🙂

         

        Stuart

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