Quantrex Academy · Free NDA PYQ solutions
NDA Mathematics Matrices 2026 NDA 2026 (Phase 1)

NDA Mathematics Question (2026) — Solution

Question

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 :

Options

  1. A. I only
  2. B. II only
  3. C. Both I and II
  4. D. Neither I nor II

Answer

B. II only

Step-by-step solution

For Statement I: If M is a symmetric matrix of order 2 2, then M^ T = M. |M+M^ T | = |2M| = 2^2|M| = 4|M| |M| + |M^ T | = |M| + |M| = 2|M| Since 4|M| 2|M| for all symmetric matrices, Statement I is incorrect. For Statement II: If M is an anti-symmetric matrix, then M^ T = -M. M+M^ T = M - M = O |M+M^ T | = |O| = 0 Statement II is correct. Answer: II only

Practice more on Quantrex App →

Related: Mathematics — Matrices · All PYQ Banks