THE WORLD OF MATRICES!

first, what is it?
matrix: a rectangular arrangement of numbers in rows and columns


Before performing any operation with matrices, you must find the dimension of the given matrix

(rows x columns) know the "run before jump" rule

ex: [ 2 3 7 5 ]

[ 6 9 3 7 ] 2 rows -------> 2 X 4

4 columns

ADD/SUBTRACT, by matching entries!

ex: [3 5] + [7 6] = [(3+7) (5+6)] = [10 11]

[4 1] [1 2] [(4+1) (1+2)] [ 5 3]

However, you cannot add or subtract a pair of matrices with different dimensions.

scalar: a real number

scalar multiplication: multiplying each entry in the matrix by the scalar

ex: 2[ 0 2 ] = [ 2(0)+2(2)] = [ 0 4 ]

[ 7 4 ] [ 2(7)+2(4)] [ 14 8]

PRACTICE PROBLEMS

1. [5 4] + [1 7 2]

[1 0] [3 9 3]

2. [3 4] _ [6 0]

[7 8] [7 4]

3. 4[2 6]

[4 9]

4. 7[1 6]

[3 2]

5. 3[1 7] + [3 1]

[3 2] [6 2]