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Vectors Help

Question 5 [20 marks]. Let
A =


0 −1 3
1 0 −3
1 2 0

, B =


3 −2
−3 1
2 −1

and C =


−2 −2 3
2 1 0
−1 1 −2

.
(a) For each of the expressions B
2
, BA, CB, CA, A−4B, and −A+5C, state whether or not
it exists, and if it exists then evaluate it.
Reply 1
Original post by theoneandonlyyo
Question 5 [20 marks]. Let
A =


0 −1 3
1 0 −3
1 2 0

, B =


3 −2
−3 1
2 −1

and C =


−2 −2 3
2 1 0
−1 1 −2

.
(a) For each of the expressions B
2
, BA, CB, CA, A−4B, and −A+5C, state whether or not
it exists, and if it exists then evaluate it.

your formatting hasn't come out very well - are these supposed to be matrices or something else? Can you upload a picture of the question?
Original post by davros
your formatting hasn't come out very well - are these supposed to be matrices or something else? Can you upload a picture of the question?

Yes sorry about that.1000004413.jpg
What have you tried? Looks like a standard "can you do matrix addition/multiplication" exercise.

In case you forgot a quirk about matrix algebra...

Spoiler

Reply 4
Original post by theoneandonlyyo
Yes sorry about that.1000004413.jpg

As tony says, this is just a "bookwork" question - what rules need to be satisfied so that you can add or multiply two matrices? This should be in your textbook or course notes; failing that, a quick google will probably tell you the answer on the first line of the search results :smile:

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