unit 1.11 - matrices

Question 1

what does 3 by 4 mean ?

Answer 1

3 rows , 4 columns

Question 2

what is ➡️ ?

what is ⬇️ ?

Answer 2

➡️ : row

⬇️ : column

Question 3

what is a square matrix ?

Answer 3

1) has the same exact amount of rows and columns
e. g; 2 by 2 matrix , 3 x 3 matrix

2) diagonal matrices
- elements except those in the leading diagonal are zero

Question 4

what is null matrix ?

Answer 4

all elements in the matrix is zero

Question 5

addition and subtraction

Answer 5

1) can only be added (subtracted) when in the same order

2) addition of 2 matrices (A) and (B) , the element of (A) must be corresponding to the element of (B)

Question 6

multiplication

Answer 6

when multiplying 2 matrices must hv a similar column (of the first pair) and row (of the second pair)

e.g; in rows and column order

m x n x n x p = m x p
- (the common would be the 2 ns , the n in the column of the first pair and the row of the second pair)