Zero Matrix
High School
Definition
When you come across a matrix that has all 0's as its elements. They are also sometimes known as null matrices. "O" is used to denote a zero matrix and a small subscript next to it (i.e. 2x4) can depict the dimensions of the matrix if needed.
Worked examples
\(O_{2\times3} = \begin{bmatrix} 0 & 0 & 0 \)
\( 0 & 0 & 0 \end{bmatrix}\)
\( 0 & 0 & 0 \end{bmatrix}\)
A 2×3 zero matrix — every entry is zero.
\(\begin{bmatrix} 1 & 2 \)
\( 3 & 4 \end{bmatrix} + \begin{bmatrix} 0 & 0 \)
\( 0 & 0 \end{bmatrix} = \begin{bmatrix} 1 & 2 \)
\( 3 & 4 \end{bmatrix}\)
\( 3 & 4 \end{bmatrix} + \begin{bmatrix} 0 & 0 \)
\( 0 & 0 \end{bmatrix} = \begin{bmatrix} 1 & 2 \)
\( 3 & 4 \end{bmatrix}\)
Adding a zero matrix to any matrix leaves it unchanged — it's the additive identity.
Common mistakes
- \(O_{2\times3} = \begin{bmatrix} 0 & 0 \)
\( 0 & 0 & 0 \end{bmatrix}\) → \(O_{2\times3} = \begin{bmatrix} 0 & 0 & 0 \)
\( 0 & 0 & 0 \end{bmatrix}\) 2×3 means 2 rows and 3 columns — each row must have exactly 3 entries. - A zero matrix can have any mix of 0's and blanks. → Every single element must be exactly 0. Blank spaces or missing entries are not valid — write an explicit 0 in every position.
Where you'll use it next
Zero matrices appear when solving systems of equations, finding matrix inverses, and working with vector spaces in linear algebra. They also serve as the additive identity in abstract algebra.
Found in 1 StudyPug lesson
Understanding Zero Matrices: The Cornerstone of Linear Algebra
12th Grade12thGrade 12 Math
Dive into the world of zero matrices! Discover their unique properties, practical applications, and crucial role in linear algebra. Enhance your math skills with clear explanations and examples.
See also
Identity MatrixElement of a MatrixMain Diagonal of a MatrixAdditive Inverse of a matrixEchelon Form of a MatrixScalar
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026