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Subject: solving equations with a matrix
Date: Sun, 4 Apr 2010 03:12:06 +0000 (UTC)
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Hi,
    I am trying to solve two 3 term equations with matrices the first one is not a problem as it is linear.
The equations are Ra+Rb=250
                          Rb+Rc=500
                          Rc+Ra=300
But the second one has terms which are to the power of negative 1, and I don't know how or indeed if they can be setup in a matrix to be solved.
The equations are (Z1^-1+(Z2+Z3)^-1)^-1=300
                          (Z2^-1+(Z1+Z3)^-1)^-1=250
                          (Z3^-1+(Z1+Z2)^-1)^-1=500
The equations are used in 3 phase power engineering, the one above is for a delta model, the one above that is for a star model
The one I'm not having a problem with is for a star model, and its values can be used to find the values of the above equations by inserting them into another set of equations Z1=Ra+Rc+((Ra*Rc)/Rb)
              Z2=Ra+Rb+((Ra*Rb)/Rc)
              Z3=Rb+Rc+((Rb*Rc)/Ra)
I can solve the delta model directly with a calculator but I would perfer to be able to show my working for exams.

So my question is can the second set of equations be solved with matrices, and if so how??
Cheers Darryl