ExamBro
ExamBro
TS EAMCET · Maths · Matrices

The inverse of the matrix \(\left[\begin{array}{ccc}7 & -3 & -3 \\ -1 & 1 & 0 \\ -1 & 0 & 1\end{array}\right]\) is

  1. A \(\left[\begin{array}{lll}1 & 1 & 1 \\ 3 & 4 & 3 \\ 3 & 3 & 4\end{array}\right]\)
  2. B \(\left[\begin{array}{lll}1 & 3 & 1 \\ 4 & 3 & 8 \\ 3 & 4 & 1\end{array}\right]\)
  3. C \(\left[\begin{array}{lll}1 & 1 & 1 \\ 3 & 3 & 4 \\ 3 & 4 & 3\end{array}\right]\)
  4. D \(\left[\begin{array}{lll}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4\end{array}\right]\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\left[\begin{array}{lll}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4\end{array}\right]\)

Step-by-step Solution

Detailed explanation

Let \[ A=\left[\begin{array}{ccc} 7 & -3 & -3 \\ -1 & 1 & 0 \\ -1 & 0 & 1 \end{array}\right] \] Now, \[ \begin{aligned} |A| & =7(1-0)+3(-1-0)-3(0+1) \\ & =1 \end{aligned} \] Cofactors of matrix \(A\) are…