This document introduces matrices and common matrix operations such as addition, subtraction, and scalar multiplication. It defines what a matrix is, how they are represented and named, and how to identify specific elements. The key matrix operations covered are addition/subtraction of matrices of the same size by adding corresponding elements, and scalar multiplication which multiplies each element of a matrix by a constant value. Examples are provided to demonstrate performing these operations on sample matrices.

1. Ch.8.5_MatrixOperations.notebook March 05, 2012
Chapter 8.5
Intro to Matrices
and Matrix Operations
Vocab:
Matrix ­ a rectangular array of numbers
Dimensions ­ # of rows & columns in a matrix
Element ­ individual entry in a matrix
Matrices are "named" Element
with a capital letter
3 4 1
A2x3 = 2 5 3
Dimensions are written
as row x column
Identify the following elements
A12 A23 A11

2. Ch.8.5_MatrixOperations.notebook March 05, 2012
Matrix Operations
Addition/Subtraction
Matrices of the SAME SIZE can be
added or subtracted by adding
corresponding elements
1 5 ­2 3
A3x2 = 2 2 B3x2 = 5 ­2
4 3 0 1
1+­2 5+3
A+B3x2 = 2+5 2+­2 A+B3x2 =
4+0 3+1
Matrix Operations
Scalar Multiplication
Elements of a matrix can be multiplied
by a constant called a scalar
1 5
A3x2 = 2 2
4 3
1(3) 5(3)
3A3x2 = 2(3) 2(3)
4(3) 3(3)
3A3x2 =

3. Ch.8.5_MatrixOperations.notebook March 05, 2012
Find the following
2A + C =
C ­ D =
3B ­ 2D =

4. Ch.8.5_MatrixOperations.notebook March 05, 2012
Page 360
#1­18 all