Operations of Matrices

What are the dimensions of this matrix?

• 4x3

• 3x4

• 3

• 4

• 
• 
• 
• 

Add

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

What is a Matrix?

• An equation of over 5 numbers or symbols 
• A set of numbers in rows and columns
• A method of finding the n^th value of a series
• A complicated number system

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

How many rows are in a 7 x 3 matrix?

• 7
• 3
• 21
• 10

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  

The number of columns in a 2x12 matrix is?

• 10
• 24
• 12
• 2

Find B-A

• -4     0
  6     -1
• 1     0
  1     -4
• 4       0
  -6     1
• not possible because rows do not match columns

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.