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03-11-2020
07:04 AM

03-11-2020
07:04 AM

1 ACCEPTED SOLUTION

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03-12-2020
10:46 AM

03-12-2020
10:46 AM

Create a 2 element vector and put in the equations. It's simple.

Success!

Luc

6 REPLIES 6

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03-11-2020
08:07 AM

03-11-2020
08:07 AM

Re: two eq. with two unknows.

Well, first you must assume that c3 is constant. . .

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03-11-2020
08:46 AM

03-11-2020
08:46 AM

Re: two eq. with two unknows.

I think that Prime cannot solve a solve block symbolically.

But if you write it simply like this:

You get your answer, for c1 and c2 in terms of the other items in the equations.

Note that u3 is common to both equations, so your problem can also be described with:

This gives you a free choice for c1, then with u1, u2, c3 and l known, you can calculate c2.

Success

Luc

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03-11-2020
09:08 AM

03-11-2020
09:08 AM

Re: two eq. with two unknows.

@LucMeekes wrote:

I think that Prime cannot solve a solve block symbolically.

That's correct. It would be possible to do so in real Mathcad (=Mathcad 15 and below) but they destroyed this possibility when they developed Prime. So the only way is to use the symbolic "solve" command as you had shown.

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03-12-2020
07:10 AM

03-12-2020
07:10 AM

Re: two eq. with two unknows.

I don't understand, how do you put it like that, in a matrix or what?

Can you maybe send the mathcad file..

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03-12-2020
10:46 AM

03-12-2020
10:46 AM

Create a 2 element vector and put in the equations. It's simple.

Success!

Luc

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03-12-2020
11:06 AM

03-12-2020
11:06 AM

Re: two eq. with two unknows.

There's more wrong with your sheet.

You define two equations with c1, c2, u1, u2 etc. these symbols are all labelled as constants.

Then you write the Find function where you want to solve c1 and c2, but these are labeled as <nothing>.

NOTE that a constant c1 is very different from a variable c1, or a unit c1 (if that would be defined).

Written like this, Prime can never solve it.

Success!

Luc