Question

Matrices

Find B^3, if possible

Answer 1

you can either try diagonalization, or just run (BB)B

Answer 2

Well I am confused with how would you find each number would you just square 2? and then you would get 8... Or is there more behind it

Answer 3

no, you would work the product like normal; BB, take the dot product of row1.col1; row2.col1; row3, col1 ... and repeat for each column

Answer 4

so with that would you take for the first dot multiply each and then add all of the numbers together?

Answer 5

http://easycalculation.com/matrix/matrix-multiplication.php

Answer 6

2 5 1
-------
2 4 1
5 0 -2
1 -1 3



4 20 1 = 25
10 0 -2 = 8
2 -5 3 = 0
for BB col1

Answer 7

\[\Large \left[\begin{matrix}{2}&{4}&{1}\\{5}&{0}&{-2}\\{1}&{-1}&{3}\end{matrix}\right]\]
For your convenience LOL
^_^

Answer 8

So the answer would be D because for the first row it would match up

Answer 9

B does seem like the most plausible, but do the other values match up?

Answer 10

http://easycalculation.com/matrix/matrix-multiplication.php @DarkBlueChocobo

Answer 11

You need to learn matrix multiplication @DarkBlueChocobo
Because, well, because XD

It might come in handy ;)

Answer 12

B might not match up ... i was blinded by your logic lol

Answer 13

Omy

Answer 14

it's A, and you only have to do 6 calculations to find itsince it gives you options

Answer 15

@DarkBlueChocobo
CAN you multiply matrices? :D
Yes or No would suffice, and if yes, then, outright multiply them :D

Answer 16

Yes lol I can I was just making sure the way I was doing it right

Answer 17

What is your way?

Answer 18

4 0 -1
-------
2 4 1
5 0 -2
1 -1 3


8 0 -1 = 7
20 0 2 = 22
4 0 -3 = 1



1 -2 3
-------
2 4 1
5 0 -2
1 -1 3


2 -8 3 = -3
5 0 -6 = -1
1 2 9 = 12

D seems to be B^2

Answer 19

Define DB :) or is it BD?

Answer 20

I thought so, and I take the 1st row and then multiply it by the 1st column, and then the 1st row by the 2nd column

Answer 21

and so on

Answer 22

yes, thats the tedium of it all

Answer 23

Oh okay then, no worries :)

Answer 24

It is so annoying. I hate this chapter

Answer 25

Matrices are nauseating :>

Answer 26

there is something about diagonalization that i vaguely recall tha tmight apply, but then you ahve to find eugene vectors and values etc

Answer 27

Yes ._. it makes table flipping rage

Answer 28

eugene vectors? LOL :>

Answer 29

I think you are confused in matrices @DarkBlueChocobo watch some online videos on matrices

Answer 30

|2 4 1| |2 4 1| |25 7 -3|
|5 0 -2| |5 0 -2|= |8 . . |
|1 -1 3 | |1 -1 3 | |0 . . |


|25 7 -3| |2 4 1| |82 * *|
|8 . . | |5 0 -2| = | * * *|
|0 . . | |1 -1 3 | | * * *|


#late to the party

Answer 31

lol

Answer 32

Thanks for all the help

Answer 33

:p I can continue now

Answer 34

yeah, BD = DB, 82 is the good one for me as well