Question

If the value of a third order determinant is 11, then the value of the square of the determinant formed by the co-factors will be

• A. 11
• B. 121
• C. 1131
• D. 14641

Answer 1

Answer: (D)

14641

Answer 2

$\Delta' = \Delta^{3-1}=\Delta^{2}= \left(11\right)^{2} =121$ $\left[\therefore \, \Delta'.\Delta = \Delta^{3}\right]$ $\therefore \, \left(\Delta'\right)^{2} = \left(121\right)^{2} = 14641$