babeeb0oL

2021-01-02

Find if possible the matrices:

a) AB

b) BA

$A=\left[\begin{array}{c}-1\\ -2\\ -3\end{array}\right],B=\left[\begin{array}{ccc}1& 2& 3\end{array}\right]$

a) AB

b) BA

broliY

Skilled2021-01-03Added 97 answers

Step 1

Given that:

The matrices,

Step 2

We know that,

Finding the product of two matrices is only possible when the inner dimension are same , meaning that the number of columns of the first matrix is equal to the number of rows of the second matrix.

a) To find AB :

Let,

Number of columns of first matrix (A) is 1 .

Number of rows of the second matrix is 1.

To get,

Step 3

Number of columns of

Then,

To get,

b) To find BA :

Number of columns of first matrix B is 3 and number of rows of matrix A is 3 which are equal .

Then,

Step 4

Therefore,

a)

b)

Jeffrey Jordon

Expert2022-01-22Added 2575 answers

Answer is given below (on video)