Question

If A is a square matrix such that A (adj A)  5I, where I denotes the identity matrix of the same order. Then, find the value of |A|.

Answer 1

We know 
\[A(adj A) = \left| A \right|I\] 
Here 
\[A(adj A) = 5I\]
\[ \therefore \left| A \right| = 5\]