Hi,

I am a bit stumped with a what is probably a simple problem. I have a root solve in Mathcad that I just cant get to work in Smath, I have tried what I think is correct ways, but still not working, see below for example:



I have also tried stripping out the units, but still no luck
Hoping someone has the simple solution.
Ian

Always plot before solving !

Solve UNK.sm (212,45 KiB) scaricato 1151 volta(e).

Wrote

Hi,

I am a bit stumped with a what is probably a simple problem. I have a root solve in Mathcad that I just cant get to work in Smath, I have tried what I think is correct ways, but still not working, see below for example:



I have also tried stripping out the units, but still no luck
Hoping someone has the simple solution.
Ian

I have tried on Mathcad and it didn't work either.
Obviously there is a mistake with the formula.
You can't add kg*N/s^2 with kg/s^2. Units mismatch.
But if you divide the givens you can get the correct answer.
If this approach is true of course since we don't have more information.

Regards.

Jean, direct question;
Are you being sarcastic about my comment?

Wrote

Jean, direct question;
Are you being sarcastic about my comment?

I have removed my comment.
In my times, maths were unitless working well.
Now, put units in maths ... red results.

Wrote

Hi,

I am a bit stumped with a what is probably a simple problem. I have a root solve in Mathcad that I just cant get to work in Smath, I have tried what I think is correct ways, but still not working, see below for example:

I have also tried stripping out the units, but still no luck
Hoping someone has the simple solution.
Ian

Hi. Your setup is correct for Mathcad, but unfortunately SMath's solvers do not works like in Mathcad, and needs some help for use units.

SolveWithUnits.sm (16,17 KiB) scaricato 1144 volta(e).



Best regards.
Alvaro

I have checked with changing all inputs;
somehow the two formula give same calculation every time.

Regards

Hi All,

Thanks for the help with this, I like the solution by Alvaro, seems the most elegant.

Unless you don't agree with yourself, solving SQRT implies the two solutions.
Presumably delimiting the range of the solvable project.

Wrote

I have checked with changing all inputs;
somehow the two formula give same calculation every time.

Regards

Hi Overlord. You found an amazing symbolic solution for the original problem. I can't explain why, but my guess is that f1, f2 and f3 must to be related with the directors cosines or something like that.

Maple shows that your solution and the symbolic solution are the same, but must to force some "not-always-true" reductions in maple, with the command "maple(simplify(expression,symbolic))"

SolveWithUnits overlord.sm (35,13 KiB) scaricato 1176 volta(e).
SolveWithUnits overlord.pdf (97,32 KiB) scaricato 806 volta(e).

Best regards.
Alvaro.

Once Maxima and the Maxima plugin are installed, you have a symbolic solver without unit issues.


solve.sm (9,99 KiB) scaricato 1141 volta(e).