How do I fill out a matrix with dots?

Question

I want to illustrate the use of dots in LaTeX.

Here is the output I am looking for:

This is the code I am starting with:

   $$
  L= \left[
  \begin{array}{ccc}
  1 & 0 & 0 \quad\cdots\quad0\\
  m_{2,1} & 1 & 0 \quad\cdots\quad0\\
  m_{3,1} & m_{3,2} & 1 \quad\cdots\quad0\\
   \\
  \end{array}  
   \right]
  $$

Please see Why is \[ … \] preferable to $$ … $$? — Werner, Jan 02 '20 at 17:09
your title asks about \dots (a command defined by amsmath) but your example code and accepted answer demonstrates \cdots do you want to change the title? — David Carlisle, Jan 02 '20 at 19:32
@constantinosgeorgiou: You can edit your title by selecting the "edit" button at the bottom left of the question. Since you posted it, you should have edit privileges on it. — Peter Grill, Jan 02 '20 at 20:57

Zarko · Accepted Answer · 2020-01-02T17:15:53.773

With use of the amsmath package (for bmatrix):

\documentclass{article}
\usepackage{amsmath}

\begin{document}
    \[
L=  \begin{bmatrix}
    1   &   0       & 0         & \cdots    & 0\\
m_{2,1} &   1       & 0         & \cdots    & 0\\
m_{3,1} & m_{3,2}   & 1         & \cdots    & 0\\
\vdots  & \vdots    & \vdots    & \ddots    & \vdots\\
m_{n,1} & m_{n,2}   & \cdots    & m_{n,n-1} & 1
  \end{bmatrix}
    \]
\end{document}

How do I fill out a matrix with dots?

1 Answers1