14-1

14-1 Matrices
In this section we learn how to add and subtract matrices, and multiply matrices using scalar multipication. This is all very simple, and there's only a few things to remember in this section:

• The matrices being added/subtracted must have the same dimensions (row x column).



• To add matrices, you add corresponding entries. Do the same when subtracting.



• To use scalar multipication, you multiply every entry by the outside number.




• A^t means transpose, which is where you swich the rows and columns.

Example 1: [2 -6] + [3 4] = [5 -2]

Example 2: [9 5] - [-1 2] = [10 3]

Example 3: Find 4A. A = [3 2 -5]

4[3 2 -5] = [12 8 -20]

Example 4: Find 2A + B. A = [4 7] B = [-2 6]

2[4 7] + [-2 6] = [8 14] + [-2 6] = [6 20]

--Jordan:)