1. Matrix Operations
Monday, August 06, 2018

2. What is a Matrix?
MATRIX: A rectangular arrangement of numbers in rows and columns.
The ORDER of a matrix is the number of the rows and columns.
The ENTRIES are the numbers in the matrix.
This order of this matrix is a 2 x 3.
columns
rows
Monday, August 06, 2018

3. What is the order? (or square matrix) 3 x 3 (Also called a row matrix)
(Also called a column matrix)
Monday, August 06, 2018

4. Adding Two Matrices
To add two matrices, they must have the same order. To add, you simply add corresponding entries.
Monday, August 06, 2018

5. = 7 7 4 5 = 7 5 7
Monday, August 06, 2018

6. Subtracting Two Matrices
To subtract two matrices, they must have the same order. You simply subtract corresponding entries.
Monday, August 06, 2018

7. 2-0 -4-1 3-8 -5 2 -5 8-3 0-(-1) -7-1 5 -8 1 1-(-4) 5-2 0-7 5 3 -7 = =
Monday, August 06, 2018

8. Multiplying a Matrix by a Scalar
In matrix algebra, a real number is often called a SCALAR. To multiply a matrix by a scalar, you multiply each entry in the matrix by that scalar.
Monday, August 06, 2018

9. -3 3 -2 6 -5
-2(-3)
-2(3) 6 -6
-12
-2(6)
-2(-5) 10
Monday, August 06, 2018

10. Multiplying Matrices
Monday, August 06, 2018

11. Scalar Multiplication - each element in a matrix is multiplied by a constant.
Monday, August 06, 2018

12. **Multiply rows times columns.
**You can only multiply if the number of columns in the 1st matrix is equal to the number of rows in the 2nd matrix.
They must match.
Dimensions:
3 x 2
2 x 3
Monday, August 06, 2018
The dimensions of your answer.

13. Examples: 2(3) + -1(5) 2(-9) + -1(7) 2(2) + -1(-6) 3(3) + 4(5)
3(-9) + 4(7)
3(2) + 4(-6)
Monday, August 06, 2018

14. *They don’t match so can’t be multiplied together.*
Dimensions: 2 x x 2
*They don’t match so can’t be multiplied together.*
Monday, August 06, 2018

15. 2 x 2 2 x 2 0(4) + (-1)(-2) 0(-3) + (-1)(5) 1(4) + 0(-2) 1(-3) +0(5)
*Answer should be a 2 x 2
2 x 2 2 x 2
0(4) + (-1)(-2)
0(-3) + (-1)(5)
1(4) + 0(-2)
1(-3) +0(5)
Monday, August 06, 2018