Question

PLEASE HELP!!! Does anyone know how to do "Matrices" It's in algebra

Answer 1

\[spose:~A=(a_1~a_2)~and~B=\binom{b_1}{b_2}~then~AB=a_1b_1+a_2b_2\]

Answer 2

if we let A have so many Rows, and B have so many columns then:

then AB is:

\[Row_1.Col_1~~Row_1C.Col_2~~Row_1.Col_3\\
Row_2.Col_1~~Row_2C.Col_2~~Row_2.Col_3\\
Row_3.Col_1~~Row_3C.Col_2~~Row_3.Col_3\\
\]

Answer 3

To multiply A and B you can think of sending the rows of B into the columns of A by kind of rotating B counter clockwise.

In your diagram, the result of AxB will be a 3x3 matrix as follows:

(8*5 + 2*6), (0*5 + 6*6), (-3*5 + 4*6)
(8*2 + 2*3), (0*2 + 6*3), (-3*2 + 4*3)
(8*-4 + 2*0), (0*-4 + 6*0), (-3*-4 + 4*0)

Answer 4

what one is that for?

Answer 5

Question (7) specifically, but the technique can be used in general and is what Amistre64 has stated quite nicely.