Construct a`2xx2` matrix A whose elements are given by `a_(ij)=1/2(i-2j)^2`

Explanation

To construct a \(2 \times 2\) matrix \(A\) whose elements are defined by \(a_{ij} = \frac{1}{2}(i - 2j)^2\), we will follow these steps:

### Step 1: Define the matrix structure
We know that a \(2 \times 2\) matrix has the following structure:
\[
A = \begin{pmatrix}
a_{11} & a_{12} \\
a_{21} & a_{22}
...