Question

In the matrix $\left[\begin{array}{cccc}2& 5& 19& -7\\ 35& -2& \frac{5}{2}& 12,\\ \sqrt{3}& 1& -5& 17\end{array}\right]$,write
(i)the order of the matrix

(ii)The number of elements,

(ii)The elements $a_{13},a_{21},a_{33},a_{24},a_{23}.$

Answer 1

In the given matrix, the number of rows is 3 and the number of columns is 4. Therefore, the order of the matrix is $3\times 4$.

Since, the order of the matrix is $3\times 4,$ so there are $3\times 4=12$ elements in it.

Let $\left[\begin{array}{cccc}2& 5& 19& -7\\ 35& -2& \frac{5}{2}& 12\\ \sqrt{3}& 1& -5& 17\end{array}\right]=\left[\begin{array}{cccc}{a}_{11}& a_{12}& a_{13}& a_{14}\\ a_{21}& a_{22}& a_{23}& a_{24}\\ a_{31}& a_{32}& a_{33}& a_{34}\end{array}\right]$
On comparing the corresponding elements, we get
$a_{13}=19,a_{21}=35;a_{33}=-5;a_{24}=12;a_{23}=\frac{5}{2}.$