Basic Matrix Operations

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.

Dimensions?

• a

• b

• c

• d

Add

• 11    8
  -4     2

• 3     2
  -6    -6

• -3    2
  -4    -6

• 10    8
  -6    2

Find A+B

• 8     10
  8      1 

• 12     25
  7     1

• 10     30
  0     1

• can't add two together because the rows dont match columns

Determine A + B

• [-1    -2    3]
  [9     -1      3]

• [-1     2      3]
  [-9      1      3] 

• [-1     2      3]
  [-9      -1      3] 

• Undefined

Element Address?

• a

• b

• c

• d

In Matrix R (pictured) what is the value of element R_3,2

• 8

• 9.01

• 6

• 1

Can the operation be performed?

• Yes

• No

• Sometimes

• only Mr. Martinez knows

How would a scalar multiplication be carried out for a matrix?

• Add the Scalar to every element in the matrix

• Subtract the elements in the first matrix from the elements of the second matrix

• Multiply every element with the scalar to create a new matrix

Find A+B

• 8     10
  8      1 

• 12     25
  7     1

• 10     30
  0     1

• can't add two together because the rows dont match columns