# What does this notation mean?

• Feb 8th 2011, 10:37 AM
cb220
What does this notation mean?
Hi, I'm working through a Linear Algebra textbook and I've run into a notation that I can't seem to find explained in the textbook. At least, I think it's a notation?

Basically, I was given two arrays like:

........2 0 3
A =..4 2 3
........5 3 2

........5 0 4
B = ..7 3 3
........2 3 1

(numbers are made up, if it matters I can dig up the actual numbers)

The first things I had to do with this was figure out 2A - 2B, this was all well and good.

The second thing I had to do was figure out $\displaystyle 5A^T$. There is the issue, I'm not sure what this T is, I don't see any value assigned to T in the question and I can't find an explanation of what to do with T in the textbook.

Does anyone know what this means? Thanks!
• Feb 8th 2011, 10:41 AM
TheEmptySet
Quote:

Originally Posted by cb220
Hi, I'm working through a Linear Algebra textbook and I've run into a notation that I can't seem to find explained in the textbook. At least, I think it's a notation?

Basically, I was given two arrays like:

........2 0 3
A =..4 2 3
........5 3 2

........5 0 4
B = ..7 3 3
........2 3 1

(numbers are made up, if it matters I can dig up the actual numbers)

The first things I had to do with this was figure out 2A - 2B, this was all well and good.

The second thing I had to do was figure out $\displaystyle 5A^T$. There is the issue, I'm not sure what this T is, I don't see any value assigned to T in the question and I can't find an explanation of what to do with T in the textbook.

Does anyone know what this means? Thanks!

It means to transpose the matrix or to exchange all of the rows and columns

$\displaystyle A=\begin{bmatrix}a& b \\ c& d \end{bmatrix}$ Then

$\displaystyle A^T=\begin{bmatrix}a& c \\ b& d \end{bmatrix}$
• Feb 8th 2011, 10:46 AM
cb220
Ah! I see, thanks for the quick response.