2/8 Multiplying Matrices

Add

• 11    8
  -4     2
• 3     2
  -6    -6
• -3    2
  -4    -6
• 10    8
  -6    2

Tags

CCSS.HSN.VM.C.8

How many rows are in a 7 x 3 matrix?

• 7
• 3
• 21
• 10

What must be true in order to ADD two matrices?

• They must be square.
• The dimensions must be equal.
• The determinant can't equal 0.
• The column of the 1st must equal the row of the 2nd.

Tags

CCSS.HSN.VM.C.8

Dimensions?

• a
• b
• c
• d

What do m, n, p and q equal in this scalar matrix multiplication?

• m=8, n=9, p=-4, q=4 
• m=15, n = -45, p=20, q=-5
• m=20, n=-5, p=15, q=-45
• m=-5, n=20, p=-45, q=15

Tags

CCSS.HSN.VM.C.7

Multiply

• 20     15    -10
  30     -5         0
• -20      15     -10
  30     -5          0
• 1        8       3
  11     4        5
• 20     -15     10
  -30         5        0  

Tags

CCSS.HSN.VM.C.7

Find the product of the two matrices.

• undefined
• -3   16
  17   12
  8   -10
• 3   12 
  -15  -8
  -1   -3

Tags

CCSS.HSN.VM.C.8

find: B*A

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

Tags

CCSS.HSN.VM.C.8

Multiply

• 1   2
  6   -8
• -3   -5
  -5   -11
• -2     8
  -6   -12
• 2  -3
  5   -2

Tags

CCSS.HSN.VM.C.8

find: B*A

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

Tags

CCSS.HSN.VM.C.8