How does one write a matrix in this forum?

[interested_learner]

I tried to enter a matrix in this forum and all I get is a big mess when I go to preview the matrix. It seems that the tool decides to get rid of the spaces in the matrix. These spaces are important. For instance if k = the rotation matrix with the first row 0 -1 and the second row 1 0

_ _
| 0 -1 |
k= |_ 1 0 _|

Does someone have a suggestion on a better way to write this?

 

[FrogPad]

Click on the following to see the code:

$$\begin{array}{cc} 1 & 0 \\ 0 & 1 \end{array}$$

If you want brackets, then:

$$\left[ \begin{array}{cc} 1 & 0 \\ 0 & 1 \end{array} \right]$$

Notice that the amount of c's control the columns, such as:

$$\left( \begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1\end{array} \right)$$

 

[FrogPad]

Oh, maybe you don't know what LaTeX is...

check this out:
https://www.physicsforums.com/showthread.php?t=8997

It's the preferred way to write math