1. Tardigrade
  2. Question
  3. Mathematics
  4. If A is a square matrix of order 3 and entries of A are positive integers then | A | is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If A is a square matrix of order 3 and entries of A are positive integers then | A | is

Matrices

Solution:

$\left|A\right| = \begin{vmatrix}5&2\\ 3&1\end{vmatrix} = 5 - 6 = - 1 $
Adj A = $\begin{pmatrix}1&-2\\ -3&5\end{pmatrix}$ if A = $\begin{pmatrix}5&2\\ 3&1\end{pmatrix} $
$\therefore $ $A^{-1} = \begin{pmatrix}-1&2\\ 3&-5\end{pmatrix}$