We are given that the determinant of a 3rd order matrix
A is
K. Hence,
∣A∣=K.
For a matrix
A, the determinant properties used here are:
The determinant of the transpose of a matrix is the same as the determinant of the matrix itself
So,
∣AT∣=∣A∣=K.
The determinant of the product of a matrix with its transpose is
∣AAT∣=∣A∣∣AT∣=K×K=K2Now, we are asked to find the sum of the determinants of matrices
A4 and
(A−A4).
Since the determinant of a product is the product of the determinants and given
∣A∣=K, we have:
∣A4∣=∣A∣4=K4.To find
∣A−A4∣, note that:
By matrix properties,
∣(A−A4)∣= simplify or evaluate separately.
Given the expresion
∣(AAT)+(A−AT)∣ in the context, we simplify:
∣AAT∣+∣A−A4∣=K2+∣A∣−∣AT∣=K2+K−K=K2.Thus the result for the sum of these determinants aligns with the property calculations stated, giving us the simplified determinant result of
K2.