(Check to make sure
that this is on your syllabus)
Matrices are tables of numbers. The numbers are put inside
big brackets. Matrices are given 'orders', which basically describe the size of
the matrices. The order is the number of rows 'by' the number of columns. So a 2
by 3 matrix has 2 rows and 3 columns.
Adding and Subtracting
Adding and subtracting matrices is fairly straight-forward. Adding and
subtracting of matrices, however, can only occur if the matrices have the same
This is a little harder than addition and subtraction. Multiplication cannot
occur between any two matrices just like addition can't occur between any two
matrices- they have to be compatible.
The rule is: if you want to multiply
two matrices, if the first matrix has order p×q (p by q) and the second has
order y×z, q must equal y or you can't multiply the two matrices. If you can
multiply, the answer will be a matrix which has order p×z.
Here is how you
would multiply a 2×3 and a 3×2 matrix:
Copyright © Matthew Pinkney 2003