Matrices

2x4 matrix means...

2 rows, 4 columns

Is matrix multiplication always commutative?

No

Zero Matrix

matrix where all elements are zeros

A^-1 is the ______________________________ of A

multiplicative inverse

Matrix addition and subtraction can only be done if the matrices have the ______________, otherwise the operation is ____________

same dimensions; undefined

For a matrix to have an inverse it must be ____________

square

If the determinant equals 0, it is...

undefined (determinant doesn't exist)

What is the determinant for 2x2 matrices?

ad-bc

What does a23 mean?

element in 2nd row 3rd column of matrix A

b34 means...

element in third row fourth column of B matrix