Class 12 Maths – Matrices Quick Revision Notes
What is a Matrix?
A matrix is a rectangular arrangement of numbers in rows and columns.
Rows = horizontal lines
Columns = vertical lines
Order of matrix = rows × columns
Types of Matrices
1. Row Matrix: Only one row
2. Column Matrix: Only one column
3. Square Matrix: Rows = Columns
4. Zero Matrix: All elements are zero
5. Diagonal Matrix: Non-diagonal elements are zero
6. Scalar Matrix: Same diagonal elements
7. Identity Matrix: Diagonal elements are 1
Equality of Matrices
Two matrices are equal if:
• Their order is same
• Corresponding elements are equal
Operations on Matrices
Addition: Possible only when order is same
Subtraction: Same rule as addition
Scalar Multiplication: Multiply every element by the scalar
Multiplication of Matrices
Two matrices can be multiplied when:
Columns of first matrix = Rows of second matrix
Important Properties
• AB ≠ BA (Not commutative)
• (AB)C = A(BC)
• A(B+C) = AB + AC
What is a Matrix?
A matrix is a rectangular arrangement of numbers in rows and columns.
Rows = horizontal lines
Columns = vertical lines
Order of matrix = rows × columns
Types of Matrices
1. Row Matrix: Only one row
2. Column Matrix: Only one column
3. Square Matrix: Rows = Columns
4. Zero Matrix: All elements are zero
5. Diagonal Matrix: Non-diagonal elements are zero
6. Scalar Matrix: Same diagonal elements
7. Identity Matrix: Diagonal elements are 1
Equality of Matrices
Two matrices are equal if:
• Their order is same
• Corresponding elements are equal
Operations on Matrices
Addition: Possible only when order is same
Subtraction: Same rule as addition
Scalar Multiplication: Multiply every element by the scalar
Multiplication of Matrices
Two matrices can be multiplied when:
Columns of first matrix = Rows of second matrix
Important Properties
• AB ≠ BA (Not commutative)
• (AB)C = A(BC)
• A(B+C) = AB + AC
