# Math Help - Matrix Problem

1. ## Matrix Problem

I'm having problems with this matrix problem. Can anyone help me?

A= 1 1
= 1 1

B= 3 -2 2
= 6 -2 3

Find A.B

2. Originally Posted by Wildman
I'm having problems with this matrix problem. Can anyone help me?

A= 1 1
= 1 1

B= 3 -2 2
= 6 -2 3

Find A.B
$A = \left[\begin{matrix}1 & 1 \\ 1 & 1\end{matrix}\right]$

$B = \left[\begin{matrix}3 & -2 & 2\\ 6 & -2 & 3\end{matrix}\right]$

$AB = \left[\begin{matrix}1 & 1 \\ 1 & 1\end{matrix}\right]\left[\begin{matrix}3 & -2 & 2\\ 6 & -2 & 3\end{matrix}\right]$

$= \left[\begin{matrix}1\cdot 3 + 1\cdot 6 & -2\cdot 1 + (-2)\cdot 1 & 2\cdot 1 + 2\cdot 3 \\ 1\cdot 3 + 1\cdot 6 & -2\cdot 1 + (-2)\cdot 1 & 2\cdot 1 + 2\cdot 3\end{matrix}\right]$

$= \left[\begin{matrix}9 & -4 & 8 \\ 9 & -4 & 8\end{matrix}\right]$

3. Thanks for the quick reply help me out alot.