Matrices Basics Flashcards
What is a matrix
a rectangular table of numbers
A matrix with 6 rows and 3 columns can be described as a
6x3 matrix
what is a square matrix
A matrix with the same number of rows and columns eg 3x3 matrix
what is the transpose of a matrix
the matrix gotten by interchanging the rows and columns of a matrix
notation for transpose of matrix
M ^T
matrix addition and subtraction can only be done when
matrices are of the same order (have same number of rows and columns)
how to add and subtract matrices
add/subtract corresponding elements
how to multiply a matrix by a scalar
multiply each element by the scalar
we can only multiply two matrices together if
the number of columns in the first column is equal to the number of rows in the second matrix
how do we multiply matrices by each other
each row of matrix 1 by each column of matrix 2
what order will the elements be in the resulting matrix of matrix multiplication
(no. rows in matrix1 x no. of columns in matrix 2)
is multiplication of matrices commutative
no
how to find the determinant of a 2x2 matrix
det(A)=ad-bc
what is a singular matrix
a matrix with determinant of 0
what is an identity matrix
A matrix with 1s in the main diagonal and 0s everywhere else
