Same chapter3 marksDifficulty: Medium
If A = [[1, 2], [3, 4]], find its transpose and state its order.
Matrices
3 marksDifficulty: Medium
If A = [[2, 1], [0, 3]] and I is the 2 × 2 identity matrix, find AI and IA and state what this shows.
Original Khojo Papers practice question — not from a past board paper.
Answer
AI = IA = A, which shows that I is the multiplicative identity for 2 × 2 matrices.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Multiplying by the identity leaves every entry unchanged, exactly as multiplying a number by 1 does.
Related questions
From the same topic and chapter, at a similar level.
Same chapter2 marksDifficulty: Medium
Give an example to show that matrix multiplication is not commutative.
Matrices
Same chapter3 marksDifficulty: Medium
If A = [[3, 1], [0, 2]], find A2.
Matrices
Same chapter3 marksDifficulty: Medium
Find the product [[1, 2], [3, 4]] × [[2, 0], [1, 3]].
Matrices
Same chapter3 marksDifficulty: Medium
Find x and y if [[x, 3], [2, y]] = [[4, 3], [2, 5]].
Matrices
Same chapter1 markDifficulty: Medium
If A is of order 3 × 2 and B is of order 2 × 3, then BA is of order:
Matrices