`if A[{:(0,3),(2,1):}],`then find `A^(2)`

Explanation

To find \( A^2 \) for the given matrix \( A = \begin{pmatrix} 0 & 3 \\ 2 & 1 \end{pmatrix} \), we will perform matrix multiplication of \( A \) with itself.

### Step-by-step Solution:

1. **Write down the matrix \( A \)**:
\[ A = \begin{pmatrix} 0 & 3 \\ 2 & 1 \end{pmatrix} \]

2. **Set up the multiplication \( A^2 = A \times A \)**:
\[ A^2 = \begin{pmatrix} 0 & 3 \\ 2 & 1 \end{pmatrix} \times \begin{pmatrix} 0 & 3 \\ 2 & 1 \end{pmatrix} \]

3. **Calculate the elements of the resulting matrix**:
- **First row, first column**:
\[ (0 \times 0) + (3 \times 2) = 0 + 6 = 6 \]
- **First row, second column**:
\[ (0 \times 3) + (3 \times 1) = 0 + 3 = 3 \]
- **Second row, first column**:
\[ (2 \times 0) + (1 \times 2) = 0 + 2 = 2 \]
- **Second row, second column**:
\[ (2 \times 3) + (1 \times 1) = 6 + 1 = 7 \]

4. **Combine the results into the resulting matrix**:
\[ A^2 = \begin{pmatrix} 6 & 3 \\ 2 & 7 \end{pmatrix} \]

### Final Result:
Thus, the square of the matrix \( A \) is:
\[ A^2 = \begin{pmatrix} 6 & 3 \\ 2 & 7 \end{pmatrix} \]