Skip to main contentSkip to solution

Match the LIST-I with LIST-II

LIST-ILIST-II
A. All positive integral powers of a symmetric matrix areI. Unit matrix.
B. Positive odd integral powers of a skew-symmetric matrix areII. Null matrix.
C. All the matrices which are both symmetric and skew-symmetric, areIII. Skew - Symmetric matrix.
D. All the square matrices whose each diagonal element is one and each non-diagonal element is equal to zero, areIV. Symmetric matrix.

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

If AT=AA^T=A then (An)T=An(A^n)^T = A^n, so powers of a symmetric matrix stay symmetric (IV).

If AT=−AA^T=-A then (An)T=(−1)nAn(A^n)^T = (-1)^nA^n, which is skew-symmetric for odd nn (III).

If AA is both, then A=−AA=-A, forcing the null matrix (II).

The described matrix is the identity, or unit matrix (I).

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question