Summary Core Pure 1 - Matrices notes (9FM0)

Matrix Array of elements

Describe size of a matrix using N of rows and
columns



square matrix N of rows and columns are the
same


zero matrix all elements are zero


identity matrix square matrix where
elements on the leading diagonal
e9 toplefts are all9 and all other
e p elements 0
are
denoted of
I where he describes size


When or subtracting matrices
adding
add or subtract corresponding elements

You can only add or subtract matrices
that are the same size
additively comfortable

, s C dy f
l Cs L's

When multiplying a matrix by a scalar
multiply every element by that scalar

Eg A 3 find 2A
At A
4 3 L 2A


Matrixnaultiplication

Matrices can be multiplied together if
N ofcolumns in est matrix Nsfrows in 2ndmatrix

Theproduct matrix will
have
same N'ofrows as Pst matrix and same
N of columns as 2nd matrix


AB C A n T
usetonbe.mgYfgipeHcativeh Be.m
xk

e i n XK

AB BA