1. All About Matrices

2. Any rectangular array of numbers in rows and columns, usually surrounded by square brackets.
The size or dimension is important.
The contents of the matrix are called its elements.
What is a Matrix?
Brackets

3. Properties of Matrices
The number of rows is always reported before the number of columns.
Rows go across Columns go up and down
Dimension:
This is a 3 x 2 matrix
Because you have
3 rows and 2 columns [ ]
2 4
6 9
5 3
Element (1,2) = 4
Element(3,2) = 3

4. This matrice has 2 rows and 3 columns.
The dimension of this matrice is (2 x 3)

5. Give the dimensions of the following matrices
Examples
Give the dimensions of the following matrices
1.)
2.)

6. Examples [ ] [ ] [ ]
12 –
4 5 6
2 3 4 4
4 6

7. Examples Construct a (2 x 4) matrice that has an element at (2, 3) = 0
1.)
Construct a (2 x 4) matrice that has an element
at (2, 3) = 0
2.)
Construct a (2 x 1) matrice that has an element at (2, 1) = -3

8. Examples
1.)
2.)

9. Discover the Math – page 52
Thomas’s Report for November Sales
white
black S T
T = T-shirts
S = sweatshirts
What does element (1,1) represent?
Row 1, Column 1
What does element (2,2) represent?
Row 2, Column 2

10. Discover the Math – page 52
Thomas’s Report for December Sales
white
black s t
T = T-shirts
S = sweatshirts
What does element (1,1) represent?
What does element (2,2) represent?

11. Discover the Math – page 52
Thomas’s Report for Nov/Dec Sales
white
black s t
T = T-shirts
S = sweatshirts
Dimensions are (2 x 2)

12. Discover the Math – page 52
Thomas’s Report for November Sales
white
black s t
T = T-shirts
S = sweatshirts
What does element (1,1) represent?
What does element (2,2) represent?

13. Adding & Subtracting Matrices
You can only add two matrices if they have the same dimension. + = =

14. Adding & Subtracting Matrices= +

15. + = YOU CANNOT ADD/SUBTRACT MATRICES WITH DIFFERENT DIMENSIONS.
Not Possible + =
(2 x 3)
(3 x 1)

16. (Scalar) x (Matrice) 3 x =
2 x =

17. Assignment Page 56 Communicate the Key Ideas 1, 3, 4