How to Create Tilted Dots in a LaTeX Matrix?

[morpheus89]

First off, don't know if this is the right section.

I've been given some homework where I should define operations of matrixes in LaTeX.

My problem is that I don't know how to do vertical dots (nor tilted to 45degrees) in the matrix.

A= \begin{pmatrix}
a_{11} & a_{12} & ... & a_{1n} \\
a_{21} & a_{22} & ... & a_{2n} \\
... & ... & & ... \\
a_{m1} & a_{m2} & ... & a_{mn}
\end{pmatrix}

the red dots must be tilted like this:

 

[Avodyne]

$$\cdots \vdots \ddots$$

 

[morpheus89]

Thank you!

 

[nusyed]

Thank you!

use \cdots for horizontal dots, \vdots for vertical dots and \ddots for diagonal dots.