Matrices

This week we learned about matrices. They are very simple.
You should know that before we start, we have some rules to go over.

Rules:

• When adding matrices, they have to be the same dimensions. (The rows and columns have to be the same. Rows x Columns).
• When you add the matrices, you add the corresponding entries together.
• Whenever you see A^t in a question/problem, it means to switch the rows and columns.

Example 1: [5 10] +[25 8]

• First, you have to see which ones are corresponding entries.
• 5 and 25 are corresponding and 10 and 8 are corresponding entries.
• Now you add those together. 5+25=30 and 10+8=18.
• Final answer: [30 18]

Example 2: What is the dimensions of [6 15 9]?

• First thing you should know is that dimensions are rows x columns.
• As you can tell this problem has one row and three columns.
• Final answer: 1x3

Example 3: Find A^t of

• So like I said above in the rules, A^t means to switch the rows and columns.
• This means you are finding a transpose of the original problem given.
• So the final answer is:

Example 4: Find 6M for [3 7 9].

• First, all you need to know is you will be multiplying 6 to each number.
• 6x3=18, 6x7=42, and 6x9=54
• Final answer: [18 42 54]

-Amber :)