1. The matrix with rows [x 2] and [8 x] is singular when
- Ax = 4 only
- Bx = ±4
- Cx = ±2
- Dx = 16
Show answer
Answer: B. |A| = x2 − 16 = 0, so x = 4 or x = −4. Forgetting the negative root gives only 4.
By Team Megalecture · Updated 4 Nov 2026
27 exam-style questions on Matrices and determinants, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
27 questions · 3 topics · 10 per test
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
Answer: B. |A| = x2 − 16 = 0, so x = 4 or x = −4. Forgetting the negative root gives only 4.
Answer: A. The minor M12 deletes row 1 and column 2: (4)(9) − (6)(7) = 36 − 42 = −6. A12 = (−1)1+2M12 = 6.
Answer: B. Each interchange of two rows (or columns) multiplies the determinant by −1.
Answer: A. Swapping the two equal rows changes the sign but leaves the determinant the same, so |A| = −|A| and |A| = 0.
Answer: C. Multiplying A by 2 multiplies every one of the 3 rows by 2, so |2A| = 23|A| = 8 × 5 = 40.
Answer: D. A singular matrix has zero determinant and so has no inverse. Non-singular means |A| ≠ 0.
Answer: C. Pre-multiply both sides by A−1: A−1AX = A−1B, so X = A−1B. Order matters because matrix multiplication is not commutative.
Answer: B. |A| = 6 − 5 = 1. Swap the diagonal entries and change the signs of the other two, then divide by 1: rows [3 −1], [−5 2].
Answer: D. The transpose of a product is the product of the transposes in reverse order: (AB)t = BtAt.
Answer: B. Hermitian means the conjugate transpose equals A. At = A is symmetric, (Ā)t = −A is skew-Hermitian, and Ā = A means the entries are real.
27, each with the answer and a short explanation, across 3 topics: Matrices and matrix algebra, Determinants, Systems of linear equations. Every chapter test draws ten of them, so you can take it many times.
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
Yes. In practice mode and on your results you can switch the explanations to Urdu.
← Chapter 2: Sets, functions and groupsChapter 4: Quadratic equations →All chaptersStuck? Ask a question