Matrices Review Multiplication

What must be true in order to MULTIPLY two matrices?

• They must be square.

• The dimensions must be equal.

• The determinant can't equal 0.

• The #of columns of the 1st must equal the # of rows of the 2nd.

When a 3x6 matrix is multiplied by a 6x5 matrix, what will the dimensions of the product be?

• 6x6

• 3x6

• 3x5

• 5x6

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• undefined

• ( 3 x 1 )

• ( 1 x 2 )

• ( 3 x 2 )

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• ( 3 x 1 )

• ( 3 x 2 )

• ( 3 x 3 )

• undefined

find: B*A

• 47     30
  9     5

• 17     15
  42     35

• 10     25
  7     1

• not possible because rows do not match columns

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• ( 2 x 2 )

• ( 6 x 2)

• ( 2 x 6 ) )

• ( 3 x 2 )

If the matrices can be multiplied, what dimension is the product? If not, write undefined.

• undefined

• ( 2 x 4 )

• ( 2 x 2 )

• ( 4 x 2 )

Perform the operation if possible.

• A

• B

• C

• D

Identify the dimensions.

• 0 x 4

• 4 x 1

• 4 x 0

• 1 x 4

Perform the scalar multiplication.

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