Entry

Definition

An entry in a matrix is an individual item or element located at the intersection of a row and a column, usually denoted as $a_{ij}$ where $i$ is the row number and $j$ is the column number.

5 Must Know Facts For Your Next Test

1. Entries are the fundamental building blocks of matrices and determine their dimensions.
2. The position of an entry is specified by its row and column indices $(i,j)$.
3. In operations such as matrix addition and multiplication, corresponding entries are combined according to specific rules.
4. A zero entry can significantly affect calculations like determinants and inverses, often simplifying computations.
5. In augmented matrices used for solving systems of equations, each entry represents coefficients or constants from the equations.

Review Questions

• How do you denote an entry located in the second row and third column of a matrix?
• What happens to the entries when two matrices are added together?
• Why is it important to pay attention to zero entries in a matrix?

Related terms

Matrix: A rectangular array of numbers arranged in rows and columns used to represent linear transformations or systems of linear equations.

Row: A horizontal line of entries in a matrix.

Column: A vertical line of entries in a matrix.