Finite Math 1.1-1.2

when a matrix’s dimension is written, ______

order is important!

the first dimension is always… ______

how many rows

the second dimension is always ______

how many columns

a position or cell in any matrix can be identified by its ____ and ____

row - column, this is called the value.

any two matrices can be added or subtracted as long as they have the same __________.

dimensions

any two matrices may be MULTIPLIED if and only if the number of columns in the first matrix and the number of rows in the second matrix are _________.

identical

any matrix plus the 0 matrix is itself

zero matrix

any matrix times the identity matrix is itself.

(the identity matrix but be a square though)

any matrix times its inverse is the ________.

identity matrix

all identity matrices are ________ matrices

square

the determinant is a _______ value that is a function of the entries of a square matrix

single

to find the determinant of a 2×2

1. times diagonal down minus diagonal up

to find the determinant of a 3×3

1. copy the 3×3 next to itself

2. start in the top left and multiple diagonally down. add them together

3. start in the bottom left and multiple diagonally up. add them together

4. diagonal down minus diagonal up