Question

If A = [a_ij] is a 2 × 2 matrix such that a_ij = i + 2j, write A.

Answer 1

$$\begin{gathered} \mathrm{Here}, \\ {a}_{ij}=i+2j,1\le i\le 2\mathrm{and}1\le j\le 2 \\ \therefore a_{11}=1+2\left(1\right)=3,a_{12}=1+2\left(2\right)=1+4=5 \\ \Rightarrow a_{21}=2+2\left(1\right)=4\mathrm{and}{a}_{22}=2+2\left(2\right)=2+4=6 \\ \therefore A=\left[\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right]=\left[\begin{array}{cc}3& 5\\ 4& 6\end{array}\right] \end{gathered}$$