Matrix Multiplication

Dimensions?

• a
• b
• c
• d

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.

You can multiply a 2X3 matrix by which matrix?

• 2X2
• 2X12
• 3X12
• 2X3

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

• 6x6
• 3x6
• 3x5
• 5x6

find: B*A

• 47     30
  9     5
• 17     15
  42     35
• 10     25
  7     1
• not possible because rows do not match columns

Matrix Multiplication is NOT defined for:

• SU
• UT
• SR
• TR

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

Perform the operation if possible.

• A

• B

• C

• D

Perform the matrix multiplication, if possible.

• 
• 
• 
• Cannot be multiplied, dimensions not compatible.