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Solve

SOLVED
lj6
Guest
Guest

Solve

Hi,

Could anyone tell me, why I'm getting just one solution when solving, when there are cleary two?

I already tried "solve, fully" btw.

 

 

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Solve

9 REPLIES 9

Re: Solve

Re: Solve

Thanks! That worked for me:)

Tags (1)

Re: Solve

The question is legitimate, as there are 10 solutions (According to Mathcad 11):

LucMeekes_0-1575801387172.png

What version of Prime are you using, and if using 6...did you choose the symbolic solver?

 

To get all real-valued t solutions for any target value of c(t) numerically, you can use:

LucMeekes_0-1575807291449.png

Equivalent Prime(3.1) file is attached.

 

Success!

Luc

Re: Solve

Maple.png

Re: Solve

Yes, that's the 10 answers Maple (and Mathcad 11) give.

Re: Solve

You could always use the numerical solver with more than one initial guess:

 

g0.jpg 

Alan

Re: Solve

t.png

Re: Solve

In the good old days Mathcad used Maple for its symbolic calculations and as you could see in Luc's post (with MC11 and Maple) Maple is able to find all solutions.

More than ten years ago Maple was replaced by MuPad and this was a big step backward. When Maple is not able to find an exact solution it switches to its own numeric mode and returns the first solution found. Modifiers like "solve, fully" or "assume,t>5" have no effect.

But it gets even worse: With Prime 6 PTC has introduced a new symbolic engine (in P6 you still can switch back to MuPad but in later Versions this will not be possible) and if you feed this engine with your problem, it calculates forever (I stopped it after two hours) and does not come up with a single solution.

 

So if you need other solutions than the one the symbolic is returning, you have to resort to Mathcads numeric methods (solve block or the root command) where you have more control by providing different guesses or a different range for root to look for.

 

Re: Solve

In the good old days: Mathcad and Maple (Adam and Eve)!

 

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