How do you know if two matrices are inverses?
Their product equals the identity matrix.
Identify element a23 from A =

What is a23 = 2
What do you know about the dimensions of two matrices that have been added together?
The dimensions are the same!
Find the mistake in their steps to find the determinant, and then say what the correct answer should have been:
[5 3
-1 2]
(5*2) + (3*-1)
(10) + (-3)
=7
They added the two products together instead of subtracting. The correct answer should be
10 - -3 = 13
How many solutions does a dependent system of equations have?
Infinitely many?
What term do we use to describe a matrix that places a column of constants in the same matrix as the coefficients.
Augmented Matrix
These are the numbers inside of a matrix.
Elements or members
What are the operation that can be performed on matrices?
Addition of Matrices
Subtraction of Matrices
Multiplication of Matrices
Which row or column would be best for finding the determinant of the matrix shown?
[1 0 -1
5 -2 7
1 6 2]
Row 1 or Column 2
No solutions
A or B must be the identity matrix.
When multiplying the following matrices(A & B), what is the output at c32?

What is c32 = 1*3 + 6*4 = 27

Simplify the following
5[1 3 5]=
5[1 3 5] = 5 x1 3x5 5x5
=[5 15 25]
The value of the determinant of a singular matrix.
0
Matrix A has elements aij. What must the value of a22 be?
7
This square matrix is the equivalent of the number 1.
The Identity Matrix
Do the following scalar multiplication and determine all elements of the result:

What is 4*(-4) 4*(3) 4*(-5)?
| -16 |
| 12 |
| -20 |
Simplify.


Will the following matrix have an inverse? How do you know?
[3 3
−1 −1]
No it will not have an inverse. You know because the determinant is zero.
Solve for y: [2 2y]+[1 0]=[3 7]
y=3.5
The dimensions of the following matrix:
What are 4 x 2?
or
What are 4 rows by 2 columns
What is the value of a13 in the following matrix after applying the scalar?

What is a13 = 20?
|-25 -30 20|
|-20 10 5 |
2C + A
What is
|7 -19|
|0 15|
The determinant of a singular matrix is 3x - 15. What must x be equal to make this true?
3x-15 =0
3x=15
x = 5
The weekly sales for 2 weeks in February for 3 models of cell phones are represented below:
Week 1 Week2
5 Model A 6 Model A
7 Model B 3 Model B
4 Model C 1 Model C
Create a 3 x 2 matrix using the information
[ 5 6
7 3
4 1]