seeking matlab mathod for solving it

• Jul 21st 2009, 11:31 PM
kurapati
seeking matlab mathod for solving it
Hi all,

I am wondering to know whether or not the following system of equations can be solved by matlab? If yes, could you please tell me how?

$A_1 X_1 = B_1 Y ; \\\\\\\
A_2 X_2 = B_2 Y ;

$

The matrices $A_1, A_2,B_1, B_2$ are 4 by 4 matrices. while the matrices $X_1,X_2,Y$ (unknown variables) are 4 by 1

I forgot to add this before : "The matrices X_1 and X_2 are made up of four variables of which the last three are same. The first one is different. and it is having a relation . The first variable in X_1 is say 'x_0' then the first variable in X_2 is [2-'x_0']"
I think : First solve for Y(dont know how) in the first equation and put it in the second equation.

• Jul 22nd 2009, 05:46 AM
BobP
These equations don't have a specific solution do they ?
What you have here are eight equations (when you equate components in the two matrix equations) in twelve unknowns, (the components of the unknowns $X1, X2, \mbox{ and } Y$ ).
It looks like you need another matrix equation or to be content with a solution containing four parameters.
• Jul 22nd 2009, 08:58 AM
CaptainBlack
Quote:

Originally Posted by kurapati
Hi all,

I am wondering to know whether or not the following system of equations can be solved by matlab? If yes, could you please tell me how?

$A_1 X_1 = B_1 Y ; \\\\\\\
A_2 X_2 = B_2 Y ;

$

The matrices $A_1, A_2,B_1, B_2$ are 4 by 4 matrices. while the matrices $X_1,X_2,Y$ (unknown variables) are 4 by 1

I forgot to add this before : "The matrices X_1 and X_2 are made up of four variables of which the last three are same. The first one is different. and it is having a relation . The first variable in X_1 is say 'x_0' then the first variable in X_2 is [2-'x_0']"
I think : First solve for Y(dont know how) in the first equation and put it in the second equation.

There is no unique solution (at least for non-singular $A_1$ and $B_2$) since if we choose any vector for $X_2$ we have:
$Y=B_2^{-1}A_2X_2$
$X_1=A_1^{-1}B_1B_2^{-1}A_2X_2$