31. If an m×n matrix B is obtained from an m×n matrix A by a finite number of elementary row and column operations, then B is said to be … to A.
A. Equal
B. Equivalent
C. Similar
D. Not equal
32. If A is invertible and AB = 0, then:
A. A = 0
B. B = 0
C. B= A
D. B is nonsingular
33. If A and B are square matrices of order n, then AB B BA is:
A. Symmetric
B. Hermitian
C. Skew Symmetric
D. All of these
34. If a matrix A is symmetric as well as skew symmetric, then A is:
A. Identity
B. Nill
C. Idempotent
D. Diagonal
36. If A^2-A-I = 0, then the inverse of A is:
A. A + I
B. A – I
C. I – A
D. -A – I
37. If A and B are square matrices of same order and A^2 – B^2 = (A + B)(A – B), then
which of the following must be true?
A. A = B
B. AB = BA
C. Either A or B is a zero matrix
D. Either A or B is an identity matrix
