Matrices Notes

Add

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

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.

Find B-A

• -3 1

  7 -1

• 1 0

  1 -4

• 4 0

  -6 1

• not possible because rows do not match columns

In Matrix R (pictured) what is r₂₃?

• 8

• 9.01

• 6

• 1

Perform the indicated operation.  If it’s not possible, select Not Possible. 

• 7
  -7
  -6
  20
• 7 
  -9
  -6
  20
• Not Possible
• 7
  -9
  2
  20

You can multiply a 2X3 matrix by which matrix?

• 2X2
• 2X12
• 3X12
• 2X3

What is a Matrix?

• An equation of over 5 numbers or symbols 
• A rectangular arrangement of numbers
• A method of finding the n^th value of a series
• A complicated number system

What is the name of each entry of a matrix?

• Row
• Element
• Dimension
• Rectangle

Given matrices A & B: 
A is a (4x33) matrix
B is a (33x1) matrix
 What are the dimensions of the product of A times B?

• 4x1
• 4x33
• 33x1
• Matrix does not exist

matrix A = 2 x 8,

matrix B = 7 x 2

Determine which of the following operations exist.

• A + B

• AB

• BA

• AB^t