State True or False for the statements
If the value of a third order determinant is 12, then the value of the determinant formed by replacing each element by its co-factor will be 144.
True
Let A be the determinant.
∴ |A| = 12
We know that if A is a square matrix of order n, then |adj A| = |A|n-1
For n = 3, |adj A| = |A|3-1
= |A|2
= 122 = 144
Hence the above statement is true.