Find the inverse of the matrix

[tex]\[
\begin{bmatrix}
4 & 3 \\
2 & 6
\end{bmatrix}
\][/tex]

If necessary, round to the nearest hundredth.



Answer :

Sure, let's find the inverse of the given matrix step-by-step, and also round the elements of the inverse to the nearest hundredth.

The original matrix is:
[tex]\[ \mathbf{A} = \begin{pmatrix} 4 & 3 \\ 2 & 6 \end{pmatrix} \][/tex]

To find the inverse of this 2x2 matrix, we can use the formula for the inverse of a 2x2 matrix:
[tex]\[ \mathbf{A}^{-1} = \frac{1}{\text{det}(\mathbf{A})} \begin{pmatrix} d & -b \\ -c & a \end{pmatrix} \][/tex]
where [tex]\(\mathbf{A} = \begin{pmatrix} a & b \\ c & d \end{pmatrix}\)[/tex], and [tex]\(\text{det}(\mathbf{A}) = ad - bc\)[/tex].

### Step-by-Step Calculation

1. Calculate the determinant of [tex]\(\mathbf{A}\)[/tex]:
[tex]\[ \text{det}(\mathbf{A}) = (4)(6) - (3)(2) = 24 - 6 = 18 \][/tex]

2. Construct the adjugate matrix:
[tex]\[ \text{Adj}(\mathbf{A}) = \begin{pmatrix} 6 & -3 \\ -2 & 4 \end{pmatrix} \][/tex]

3. Divide the adjugate matrix by the determinant to get the inverse:
[tex]\[ \mathbf{A}^{-1} = \frac{1}{18} \begin{pmatrix} 6 & -3 \\ -2 & 4 \end{pmatrix} = \begin{pmatrix} \frac{6}{18} & \frac{-3}{18} \\ \frac{-2}{18} & \frac{4}{18} \end{pmatrix} = \begin{pmatrix} 0.33333333 & -0.16666667 \\ -0.11111111 & 0.22222222 \end{pmatrix} \][/tex]

4. Round the elements of the inverse matrix to the nearest hundredth:
[tex]\[ \mathbf{A}^{-1} \approx \begin{pmatrix} 0.33 & -0.17 \\ -0.11 & 0.22 \end{pmatrix} \][/tex]

Therefore, the inverse of the matrix
[tex]\[ \begin{pmatrix} 4 & 3 \\ 2 & 6 \end{pmatrix} \][/tex]
is
[tex]\[ \begin{pmatrix} 0.33 & -0.17 \\ -0.11 & 0.22 \end{pmatrix} \][/tex]

So, filling in the missing values, we have:
[tex]\[ \begin{pmatrix} 4 & 3 \\ 2 & 6 \end{pmatrix} \quad \rightarrow \quad \begin{pmatrix} 0.33 & -0.17 \\ -0.11 & 0.22 \end{pmatrix} \][/tex]