Solving for multiple variables

[ptc-3474291]

Hey - and happy easter!

I've just started using Mathcad Prime 3, instead of mathcad 15. Horrible, I must say.
But my question here, is about symbolic solving.

I have the following equation:

And I'd really like to have all my known values at the right side of the equals sign.

These values are xa and ya - the rest I'd like to have on the left side.

Is there any function in mathcad Prime that can do that? I am aware of, it is possible doing on your own, but let's face it - I haven't done so in a lot of years, and I forgot how. And I'm stupid as a stone! (And I don't wanna do it, everytime i need to do this

I need to do it, so I can make the equations ready for a matrix.

I'd be so happy, if anyone here could help me!

Have a great day,
Ben

[Werner_E]

I've just started using Mathcad Prime 3, instead of mathcad 15. Horrible, I must say.

Any specific reason for downgrading? From time to time I have my masochisitic moments, too, but I wouldn't go that far 😉

And I'd really like to have all my known values at the right side of the equals sign.

These values are xa and ya - the rest I'd like to have on the left side.

Is there any function in mathcad Prime that can do that?

Nothing that I would be aware of. Unfortunately Mathcad's symbolics doesn't offer any way to manipulate equations like squaring both sides or adding something on both sides.

BTW, what do you think should the result look like? How would you separate x0, y0 andr on the LHS and xa and ya on the RHS? Would be interested how you would do it by hand.

[ptc-3474291]

Well, I'll still use MC15 for all my work, but for my own projects, I use Prime. Sooner or later my work is gonna dismiss MC15 and go for Prime - might as well be ready! :-

Aw. Sucks. 😞
I really don't know.

[Werner_E]

Sure a good idea to make yourself acquainted with Prime as this cumbersome UI will be the future (unless you look for alternatives as we do).

As for you question - we may conclude that you demanded the impossible (separating x0, y0 from the rest) regardless of Prime being able to manipulate equations or not.

But if you tell us what you really are after at the end, it might be possible Mathcad can help and maybe even Prime.

[ptc-3474291]

Thank you very much for all your feedback!

What I was hoping to do, was getting these equations on a form, where it would be possible to insert them into a matrix, for solving using programming.

I must say - I'm netiher strong in programming nor matrix', so this is really a great way to learn.
Thank you very much.

[Werner_E]

You wouldn't have to resort to programming to solve a system of equations. You could either use a solve block (numeric method, just one solution depending on a guess value) or the symbolics "solve" command.

You show 3 equations with 12 variables - you may solve for 3 of them.

[ptc-3474291]

Oh yeah - sorry, wrongful explanation.
I have used this for solving in theory, but I'm trying to make a microcontroller doing it - so I need to program this in c / c++ - not mathcad. My apologies. 🙂

[Werner_E · Accepted solution]

Benjamin Larsen wrote:

Oh yeah - sorry, wrongful explanation.
I have used this for solving in theory, but I'm trying to make a microcontroller doing it - so I need to program this in c / c++ - not mathcad. My apologies. 🙂

No problem, I guess Mathcad/Prime can give you what you want using symbolical solving. You have to specify what to solve for. Best you attach a sheet.

[Fred_Kohlhepp]

You have one equation and two "knowns", so you can "solve" for xa or ya, but that leaves you with expressions with all of your unknowns and one known xa = (x0^2-r^2 +y0^2 -2 y0 ya + ya^2)/(2 x0) or ya = two different terms because of the squared term.

Not sure how you planned to go from there.