Matrices | Class 12 Mathematics Notes

3.3 Types of Matrices

Matrices are classified into various types based on their order and elements. A column matrix has only one column (order m × 1), while a row matrix has only one row (order 1 × n). A square matrix has equal number of rows and columns (order n × n). The diagonal elements of a square matrix are those where row and column indices are equal (a_11, a_22, ..., a_nn). A diagonal matrix is a square matrix where all non-diagonal elements are zero. A scalar matrix is a diagonal matrix with all diagonal elements equal. An identity matrix is a scalar matrix with diagonal elements equal to 1 and zeros elsewhere, denoted by I_n. A zero matrix has all elements zero, denoted by O. Equality of matrices requires same order and equal corresponding elements.

🧪 Activity: Example 4 and 5: Finding unknowns using equality of matrices.

🔗 Connection: Prepares for matrix operations such as addition, scalar multiplication, and matrix multiplication.