Determinants Matrices Question 95

Question: If A and B be two square matrices of order $ \lambda $ whose all the elements are essentially positive integers then the minimum value of $ tr\text{ (}AB^{2}) $ is equal to

Options:

A) $ {{\lambda }^{3}} $

B) $ {{\lambda }^{2}} $

C) $ 2{{\lambda }^{2}} $

D) None of these

Show Answer

Answer:

Correct Answer: B

Solution:

  • [b] $ tr(A)=\sum\limits _{i=1}^{\lambda }{a _{ii}\ge \lambda (Asa _{ij}\ge 1i,j)} $ and $ tr(MN^{2})={tr(M)}{{{tr(N)}}^{2}} $