`M_( n )` be an n times n matrix with I in the main diagonal and directly above and below it,all other entries are zero The absolute value of detrminant of `M_(4)`is

Let M be a 2xx2 symmetric matrix with integer entries. Then M is invertible if The first column of M is the transpose of the second row of M The second row of M is the transpose of the first column of M M is a diagonal matrix with non-zero entries in the main diagonal The product of entries in the main diagonal of M is not the square of an integer

Let M be a 2 x 2 symmetric matrix with integer entries. Then M is invertible if (a)The first column of M is the transpose of the second row of M (b)The second row of Mis the transpose of the first olumn of M (c) M is a diagonal matrix with non-zero entries in the main diagonal (d)The product of entries in the main diagonal of Mis not the square of an integer

If A is a diagonal matrix of order 'n 'such that A^(2)=A. then number of possible values of matrix A is

When (m/n) = 25(n/m) , Then the value of m : n is :

If A is the n xx n matrix whose elements are all '1' and B is the n xx n matrix whose diagonal elements are all 'n' and other elements are n-r , then A^(2) is a scalar multiple of

If A is an m xx n matrix and B is n xx p matrix does AB exist? If yes,write its order.

The number of n xx n matrix A and B such that AB-BA=I is.

The number of n xx n matrix A and B such that AB-BA=I is.