Question

In the matrix $A=\left[\begin{array}{ccc}a& 1& x\\ 2& \sqrt{3}& x^2-y\\ 0& 5& \frac{-2}{5}\end{array}\right]$, write

(i) the order of the matrix A.

(ii) the number of elements.

(iii) elements $a_{23},a_{31}$ and $a_{12}$.

Answer 1

We have, $A=\left[\begin{array}{ccc}a& 1& x\\ 2& \sqrt{3}& x^2-y\\ 0& 5& \frac{-2}{5}\end{array}\right]$

(i) the order of matrix A = 3 $\times$ 3

(ii) the number of elements = 3$\times$ 3 = 9

[since the number of elements in an m $\times$ n matrix will be equal to m $\times$ n = mn ]

(iii) $a_{23}=x^2-y,a_{31}=0,a_{12}=1$

[since, we know that $a_{ij}$,is a representation of element lying in the ith row and jth column ]