Complex system of equation solver

[esteszeke]

Hey everyone, I just switched over from my Ti89 and am getting used to doing the same functions that I used too with it with the prime. 

In my Electrical Engineering courses I do a lot of complex/frequency domain analysis, and I am trying to figure out how to define a system of equations and solve for two variables. This can be done with non-complex system of equations using the solver, but this is not the case with complex numbers. An example is below.

eq1: (2 + j6)*A + (j)*B = 0

eq2: (j)*A + (j3 + 2)*B = 0

Need to solve for A and B

I also tried to do this with a matrix and row reduce, but also cannot figure out how to do this. These types of problems were easy to acomplish on the TI89 with csolve( { eq1, eq2 }, {A , B} )

Appeciate y'alls help. 

[cyrille]

Hello,

Are you sure of your equation? since here, the obvious sollution is A=B=0..

Anyhow, they are a lot of ways to solve such equation in Prime.

in CAS mode:

cSolve({(2+6*i)*a+i*b,i*a+(2+3*i)*b},{a,b})

will work.

so will

[0,0]/[[2+6*i,i],[i,2+3*i]] or (better syntax) inv([[2+6*i,i],[i,2+3*i]])*[0,0]

Note that complex numbers can be entered either as (im,re) or as im+re*i.

i needs to be used, not j.

in CAS mode, use lower case variables (as they are mathematic variables, as in letter to replace unknown numbers), while upper case A-Z variable names are more "programming" type variables. ie a letter that contains a number.

Cyrille

[esteszeke]

My problem was not setting the equations to 0. And ensuring that I am in CAS mode. 🙂 Thank you!