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02-02-2012
05:32 PM

02-02-2012
05:32 PM

Expanding equations in Solve block turns values to 0

I have (6) equations with (6) unknowns that I have in a solve block. In addition to showing the equations I am using, I have to show the equation with the known values shown

For example, the fourth equation is:

(V.S2) = (I.2) * (Z.L2)

I have put the variables in parenthesis to indicate the entire name for the purpose of the discussion.

The variables (V.S2) and (Z.L2) are already pre-defined. I would like to show the same equation next to the first euqation with the values of (V.S2) and (Z.L2) shown. When I try using the "simplify" or "expand" or "-->" next to the equation, the values in my results change to 0.

I have attached the Mathcad file. Going into the solve block and trying to expand the equation will cause the values in my results to change to zero. Can someone please provide some guidance? Thank you.

12 REPLIES 12

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02-03-2012
12:31 AM

02-03-2012
12:31 AM

Re: Expanding equations in Solve block turns values to 0

Sorry, the symbol math of Mathcad does not know units - ohm, V, deg.

See the attach

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02-03-2012
02:08 AM

02-03-2012
02:08 AM

Re: Expanding equations in Solve block turns values to 0

Valery nothing attached.

Mike

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02-03-2012
02:09 AM

02-03-2012
02:09 AM

Re: Expanding equations in Solve block turns values to 0

As Valery indicated the symbolic engine doesn't deal with units, see the attached is of help.

Mike

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02-03-2012
02:40 AM

02-03-2012
02:40 AM

Re: Expanding equations in Solve block turns values to 0

Sorry - see the attach

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02-03-2012
02:41 AM

02-03-2012
02:41 AM

Re: Expanding equations in Solve block turns values to 0

Again Valery, nothing is being attached.

Mike

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02-03-2012
02:48 AM

02-03-2012
02:48 AM

Re: Expanding equations in Solve block turns values to 0

1. Now in Mathcad Prime we can have in one vector volt and ampere

2. It is a system of LINEAR Equations and we can use the lsolve function

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02-03-2012
01:23 PM

02-03-2012
01:23 PM

Re: Expanding equations in Solve block turns values to 0

@ Mike: If the variables did not have units, could I use the symbolic engine to expand on the equations?

@ Valery: In Mathcad Prime, would the Isolve function allow me to work with units and expand the equations?

Thanks in advance.

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02-03-2012
01:39 PM

02-03-2012
01:39 PM

Re: Expanding equations in Solve block turns values to 0

@ Mike: If the variables did not have units, could I use the symbolic engine to expand on the equations?

You can tell to symbolic Math of Mathcad that V =A*ohm

@ Valery: In Mathcad Prime, would the Isolve function allow me to work with units and expand the equations?

Thanks in advance.

The Isolve function of regular Mathcad allow you to work with units of one dimentions.

The Isolve function of Mathcad Prime allow you to work with units of different dimentions.

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02-04-2012
09:27 PM

02-04-2012
09:27 PM

Re: Expanding equations in Solve block turns values to 0

Do you mean this?

Because if this is what you mean, I don't see the 0's.

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02-05-2012
12:17 AM

02-05-2012
12:17 AM

Re: Expanding equations in Solve block turns values to 0

May be so:

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02-05-2012
12:41 AM

02-05-2012
12:41 AM

Re: Expanding equations in Solve block turns values to 0

This is **one**** of the few tasks **where **Mathcad Prime **has a distinct **advantage**** **over traditional Mathcad: the solving by the help of the lsolve function or by the help of the operator A^(-1)*v a system of linear equation A*x=v where arrays A, v and x have elements with different dimensions - Potential and Current!

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02-08-2012
02:56 AM

02-08-2012
02:56 AM

Re: Expanding equations in Solve block turns values to 0

oneof the few taskswhereMathcad Primehas a distinctadvantageover traditional Mathcad: the solving by the help of the lsolve function or by the help of the operator A^(-1)*v a system of linear equation A*x=v where arrays A, v and x have elements with different dimensions - Potential and Current!

Massive, massive improvement IMO.

Mike