The matrix `[[1, a, 2], [1, 2, 5], [2, 1, 1]]` is not invertible, if a=

The matrix [[lambda, -1, 4], [-3, 0, 2], [-1, 1, 2]] is invertible, if

Matrix A=[[1, 0, -k], [2, 1, 3], [k, 0, 1]] is invertible for

Matrix of co-factors of the matrix [[1, -1, 2], [-2, 3, 5], [-2, 0, -1]] is

If A=[(1,lambda,2),(1,2,5),(2,1,1)] is not invertible then lambda =?

If A=[(1,lambda,2),(1,2,5),(2,1,1)] is not invertible then lambda =?

(i) Show that the matrix A=[[1,-1, 5],[-1, 2, 1],[ 5, 1, 3]] is a symmetric matrix. (ii) Show that the matrix A=[[0, 1,-1],[-1, 2, 1],[ 1,-1, 0]] is a skew symmetric matrix.

Is the matrix [(1, 0, 0),(1, 1, 1),(2, -1, 1)] invertible?

The matrix [(2,-1,3),(lamda,0,7),(-1,1,4)] is not invertible for

If the matrix [{:(alpha,2,2),(-3,0,4),(1,-1,1):}] is not invertible, then :

If the matrix [{:(alpha, 2,2),(-3,0,4),(1,-1,1):}] is not invertible then: