NDA 2026 · PYQ · Matrices and Determinants · medium
If M^T is the transpose of a 2 × 2 matrix M, then which of the following is/are correct? I. |M + M^T| = |M| + |M^T| if M is symmetric. II. |M + M^T| = 0 if M is anti-symmetric. Select the answer using the code given below:
A.I only
B.II only✓ Correct
C.Both I and II
D.Neither I nor II
Explanation
If M is symmetric, M^T = M, so M + M^T = 2M and |2M| = 4|M|, but |M| + |M^T| = 2|M|, so statement I is false in general. If M is anti-symmetric, M^T = -M, so M + M^T = 0 matrix, hence |M + M^T| = 0. So only statement II is correct.
💡 Practice unlimited NDA PYQs + AI-tracked progress on each topic. Sign up free →