Reference Sheet: Matrix Operations
1. State the term:Matrices
2. State the mathematical definition of the term.
A rectangular array of numbers written within brackets.
3. Explain the meaning of the term in your own words.
Matrices is a way to organize numbers in brackets and then be able to add, subtract, or multiply them with other numbers.
4. Show an example of the term and show something that looks like an example but is not. Explain what the difference between the two examples is.
To find a12 you would look for the 1st row and 2nd column. So a12= 3
2 3
4 5
Since there are 2 rows and 2 columns, this is a 2x2 matrix.
3 4 7
2 8 5
Find a12 → a12 = 2. This is wrong because the columns and rows were mixed up.
Difference:
In the second example the answer should be 4 because you should look for the first row (horizontal) and the second column (vertical).
5. Show another way that you can think about this term or something that will help you remember the concept. You may want to show a picture, graph, diagram, or drawing that will help you remember the big idea.
This is like creating a table except there are numbers inside brackets. You have rows and columns that you can use to identify terms.
This is a 3x2 matrix. Matrices can be any dimensions.
1 4
2 5
3 6
How to Write a Skill Description
1. Skill Title (A title gives you a short way to remember what the skill is)
Matrices Operations
2. Skill Description (Few sentences that describes what the skill is and what it is good for. This description should be short enough to read quickly and decide if you can use it to solve the problem you are working on.)
Add, subtract, or multiply sets of data with other pieces of data.
3. Examples (Use one or two challenging and relevant examples)
1) 2 3 -3 2 2(-3)+ 3(-5) 2(2)+ 3(-1)
-4 1 -5 -1 -4(-3)+ 1(-5) -4(2)+ 1(-1)
-6+ -15 4+ -3 -21 1
12+ -5 -8-1 7 -9
2) -3 2 4 -1 -3+4 2+ -1 1 0
-4 -9 4 10 -4+4 -9+10 0 1
If you were looking for the determinant and you plugged the matrix into a calculator and got an answer of 0 then it there are an infinite number of possibilities.
4. Application (Explain how, if you were looking at a word problem, you would know that this skill could help you solve the problem)
if your matrices have different dimensions you can't add them together. Also if you want to multiply matrices the 2nd column of the 1st matrix must be the same as the 1st row of the second matrix.
Ex of multiplication: 2x4 4x5 this works
5. Description of the process (Describe the process in a list or paragraph form. Be sure to explain the purpose of each step)
Adding: -dimensions must be the same, add the numbers that are in the same location, write the sums in their respected locations.
Subtracting: -dimensions must be the same, subtract the numbers that are in the same location, write the sums in their respected locations.
Multiplication: dimensions must be AxB BxA, multiply numbers that are in the same location, write the products in the respected locations.
Comments on the Reference Sheet
Focus on the following thing(s) for revision
1.
Need to provide a bit more detail in your explanations for each of the three operations.
2.
Need to provide examples and non-examples of each of the three operations. May want to include a section of whether the operation would be able to be performed or not.
+ Good / Change
Problem
Process