SOLUTION: can someone please help me with this problem: Find the order of the matrix product AB and the product BA, whenever the products exist. A is 2 x 1, B is 1 x 1 a. AB is 2 x

Algebra ->  Matrices-and-determiminant -> SOLUTION: can someone please help me with this problem: Find the order of the matrix product AB and the product BA, whenever the products exist. A is 2 x 1, B is 1 x 1 a. AB is 2 x       Log On


   



Question 166576: can someone please help me with this problem:
Find the order of the matrix product AB and the product BA, whenever the products exist.
A is 2 x 1, B is 1 x 1
a. AB is 2 x 1, BA is nonexistent.
b. AB is nonexistent, BA is 1 x 2
c. AB is 1 x 2, BA is 1 x 1
d. AB is 2 x 2, BA is 1 x 1

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the order of the matrix product AB and the product BA, whenever the products exist.
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Rule: The number of columns on the left must be the same as the number
of rows on the right.
The product of an [x by y matrix] and a [w by z matrix] will be x by z]
To have a product, y must bethe same as w.

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A is 2 x 1, B is 1 x 1
AB ?
Can be multiplied because 1=1
Product will be 2 x 1
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BA ?
Cannot be multiplied because 1 is not equal to 2
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Answer: a
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Cheers,
Stan H.
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a. AB is 2 x 1, BA is nonexistent.
b. AB is nonexistent, BA is 1 x 2
c. AB is 1 x 2, BA is 1 x 1
d. AB is 2 x 2, BA is 1 x 1