unit triangular matrix

A unit upper triangular matrix is of the form

\begin{bmatrix}1&a_{12}&a_{13}&\cdots&a_{1n}\\ 0&1&a_{23}&\cdots&a_{2n}\\ 0&0&1&\cdots&a_{3n}\\ \vdots&\vdots&\vdots&\ddots&\vdots\\ 0&0&0&\cdots&1\end{bmatrix}

and is sometimes called a unit right triangular matrix.

A unit lower triangular matrix is of the form

\begin{bmatrix}1&0&0&\cdots&0\\ a_{21}&1&0&\cdots&0\\ a_{31}&a_{32}&1&\cdots&0\\ \vdots&\vdots&\vdots&\ddots&\vdots\\ a_{n1}&a_{n2}&a_{n3}&\cdots&1\end{bmatrix}

and is sometimes called a unit left triangular matrix.

Title	unit triangular matrix
Canonical name	UnitTriangularMatrix
Date of creation	2013-03-22 13:41:58
Last modified on	2013-03-22 13:41:58
Owner	Daume (40)
Last modified by	Daume (40)
Numerical id	6
Author	Daume (40)
Entry type	Definition
Classification	msc 15-00
Synonym	unit left triangular matrix
Synonym	unit right triangular matrix
Defines	unit upper triangular matrix
Defines	unit lower triangular matrix