Question

Give the order of the given matrix.b.  If A=aij, identify a31 and a13, if possible.

Answer 1

Step-by-step explanation:

We are given the matrix

`\begin{bmatrix}{6} & {-4} & {8} \\ {} & {} & {} \\ {-6} & {9} & {-9}\end{bmatrix}`

The first part wants us to give the order of the given matrix

The order of a matrix is given by

`m* n=Number\text{ of rows}* number\text{ of columns}`

We have

`\begin{gathered} rows:\text{ Horizontal} \\ columns:vertical \end{gathered}`

`\begin{gathered} two\text{ rows} \\ three\text{ columns} \end{gathered}`

To the order (mxn) is:

`2*3`

Part B

We are told to find

`\begin{gathered} a_(31) \\ and \\ a_(13) \end{gathered}`

To begin with, let

`\begin{gathered} a_(31)\text{ means that we should find the element in the third row and first column} \\ a_(13)\text{ means that we should find the element in the first row and third column} \end{gathered}`

So

`\begin{gathered} a_(31):\text{ null, because there is no row 3} \\ Thus,\text{ there is no value} \end{gathered}`

Then

`\begin{gathered} a_(13):\text{ 8} \\ Because\text{ the element that coincides with the first row and third column is 8} \end{gathered}`