# solving the matrix equation

• Feb 24th 2010, 09:11 AM
anna123456
solving the matrix equation
Let A =
1 1
0 1
and B =
0 -1
1 0

Solve the following matrix equation for X:
(BA)X^T =
1 0
-1 1

I'm sorry those are suposed to be matrixes. So I know that first I have to find BA which is
0 -1
1 1
Then I know that X^T times BA is
1 0
-1 1
And after that I'm stuck(
• Feb 24th 2010, 11:42 AM
HallsofIvy
Quote:

Originally Posted by anna123456
Let A =
1 1
0 1

$\displaystyle A= \begin{bmatrix}1 & 1 \\ 0 & 1\end{bmatrix}$

Quote:

and B =
0 -1
1 0
$\displaystyle B= \begin{bmatrix}0 & -1 \\ 1 & 0\end{bmatrix}$

Click on those to see the code I used.

Quote:

Solve the following matrix equation for X:
(BA)X^T =
1 0
-1 1
$\displaystyle (BA)X^T= \begin{bmatrix}1 & 0 \\ -1 & 1\end{bmatrix}$.

Quote:

I'm sorry those are suposed to be matrixes. So I know that first I have to find BA which is
0 -1
1 1

Then I know that X^T times BA is
1 0
-1 1
And after that I'm stuck(
If Ax= C then $\displaystyle x= A^{-1}C$. Since you have already found BA, find its inverse and multiply by $\displaystyle \begin{bmatrix}1 & 0 \\ -1 & 1\end{bmatrix}$.
• Feb 25th 2010, 09:21 AM
anna123456
thank you!