|1. An array of numbers in rows and columns is called a matrix.
2. The numbers arranged in rows and columns in a matrix are called elements of the matrix.
3. [ ] or ( ) is the symbol of a matrix.
4. A matrix having only one row is called a row matrix.
5. A matrix having only column is called a column matrix.
6. A matrix having same number of rows and columns is called a square matrix.
7. A matrix with all its elements as zeros is called a Null matrix or zero matrix and it is represented by '0'.
8. A square matrix in which each of the elements in the principal diagonal is '1 and all other elements are zeros is called an identity matrix or unit matrix.
9. If the rows and columns of a matrix are interchanged, the matrix obtained is called the transpose of the original matrix and is denoted by AT.
10. The number of rows ´ the number of columns of the matrix is called the order of the matrix.
11. Two matrices are equal if the corresponding elements in both the matrices are the same.
12. The multiplication of two matrices A and B is defined if the number of columns in A is equal to the number of rows of B.
13. If a matrix is equal to its transpose it is called a symmetric matrix.
14. If the transpose of a matrix is equal to the additive inverse of the given matrix then the given matrix is called skew symmetric matrix.
15. The diagonal from the first element of the first row to the last element of the last row is called the principal diagonal of square matrix.
16. A square matrix in which all the elements in the principal diagonal are equal and the rest of the elements are zero is called scalar matrix.
17. Solving systems of equations using a variety of methods:
Directions: Choose the correct answer.