If A is a 3 \(\times\) 3 non-singular matrix such that AA^T = A^TA and B = A^-1A^T, then BB^T = 

(a)

A

(b)

B

(c)

I₃

(d)

B^T

If A = \(\left[ \begin{matrix} 7 & 3 \\ 4 & 2 \end{matrix} \right] \), then 9I₂ - A = 

(a)

A^-1

(b)

\(\frac { { A }^{ -1 } }{ 2 } \)

(c)

3A^-1

(d)

2A^-1

If A = \(\left[ \begin{matrix} 3 & 1 & -1 \\ 2 & -2 & 0 \\ 1 & 2 & -1 \end{matrix} \right] \) and A^-1 = \(\left[ \begin{matrix} { a }_{ 11 } & { a }_{ 12 } & { a }_{ 13 } \\ { a }_{ 21 } & { a }_{ 22 } & { a }_{ 23 } \\ { a }_{ 31 } & { a }_{ 32 } & { a }_{ 33 } \end{matrix} \right] \) then the value of a₂₃ is

(a)

0

(b)

-2

(c)

-3

(d)

-1

Let A be a 3 \(\times\) 3 matrix and B its adjoint matrix If |B| = 64, then |A| = ___________

(a)

±2

(b)

±4

(c)

±8

(d)

±12

If A^T is the transpose of a square matrix A, then ___________

(a)

|A| ≠ |A^T|

(b)

|A| = |A^T|

(c)

|A| + |A^T| =0

(d)

|A| = |A^T| only

\(\rho\) (A) = \(\rho\) [(A|B]) = 2 < number of unknowns

(1)

Consistent with two parameter family of solution

\(\rho\) (A) = \(\rho\) [(A|B)] = 1  < number of unknowns

(2)

In consistent and has no solution

\(\rho\) (A) ≠ \(\rho\) [(A|B)]

(3)

adj (A^T)

[adj A]

(4)

Consistent with one parameter family of solution

(adj A)^T

(5)

|A|^n-1