TeXipedia

cdots

Represents a horizontal ellipsis (three centered dots) used to indicate continuation in mathematical expressions, particularly in matrices and sequences.

Overview

Serves as a crucial notation element in mathematical writing to show pattern continuation, especially in the middle of expressions at the same vertical level as multiplication dots.

  • Commonly used in sequences, series, and matrix notation to indicate omitted terms
  • Preferred over regular dots when showing multiplication or horizontal continuation in mathematical expressions
  • Often appears in linear algebra for compact matrix representation
  • Distinguished from \ldots (low dots) and \vdots (vertical dots) by its centered alignment
  • Particularly useful in professional mathematical typesetting where precise dot placement matters

Examples

Showing the middle terms of a sequence in mathematical notation.

x1+x2+⋯+xnx_1 + x_2 + \cdots + x_n 
x_1 + x_2 + \cdots + x_n

Representing matrix elements with centered dots.

(a11a12⋯a1na21a22⋯a2n)\begin{pmatrix} a_{11} & a_{12} & \cdots & a_{1n} \\ a_{21} & a_{22} & \cdots & a_{2n} \end{pmatrix} 
\begin{pmatrix} a_{11} & a_{12} & \cdots & a_{1n} \\ a_{21} & a_{22} & \cdots & a_{2n} \end{pmatrix}

Indicating multiplication of multiple terms.

x1⋅x2⋅⋯⋅xn=∏i=1nxix_1 \cdot x_2 \cdot \cdots \cdot x_n = \prod_{i=1}^n x_i 
x_1 \cdot x_2 \cdot \cdots \cdot x_n = \prod_{i=1}^n x_i