# Thread: Matrix =

1. ## Matrix =

Code:
[1  5]  [4  -2]
[-2 3]  [0   1]
My answer is
Code:
   [5   3]
[-2  4]
Thanks for checking my answer.

2. Originally Posted by kwtolley
Code:
[1  5]  [4  -2]
[-2 3]  [0   1]
My answer is
Code:
   [5   3]
[-2  4]
Thanks for checking my answer.
Can't be as the top left element of the product is the dot product of the
first row of the first matrix and the first column of the second, hence it
is:

$\displaystyle [1,\ 5] \cdot [4,\ 0]=4$,

but your answer has $\displaystyle 5$ for this element.

RonL

3. Originally Posted by kwtolley
Code:
[1  5]  [4  -2]
[-2 3]  [0   1]
My answer is
Code:
   [5   3]
[-2  4]
Thanks for checking my answer.
This is correct if you're adding the matrices together.

4. Originally Posted by Quick
This is correct if you're adding the matrices together.
I suppose that is possible, maybe I lost something in reformatting the
question that make this interpretation more likely.

RonL

5. ## no adding

This problem is written just like I posted it, so I'm not sure if I should have added, but I did. Thanks as always for checking.

6. Originally Posted by kwtolley
This problem is written just like I posted it, so I'm not sure if I should have added, but I did. Thanks as always for checking.
If there is no addition sign between the matrices then the question is
asking for the matrix prooduct, which is what my answer refered to.

RonL