UNIT 2 : WHAT IS A MATRIX – REALLY?

Sec 1: Organizing Data into Matrices

Learning Target: I will organize information using matrices, give dimensions of a matrix and identify elements of a matrix.

Homework: Organizing Data into Matrices Worksheet

What do you think a matrix is?

DEFINITION

Matrix (plural: matrices) –

a rectangular array of

numbers written within

brackets.

THINGS YOU CAN DO WITH A MATRIX

Organize Information

Add, Subtract and Multiply to find quantities

quickly with large groups of information.

Find missing quantities

Solve systems of equations

Transform geometric figures: rotate, reflect,

translate

EX 1: DIMENSIONS

The number of horizontal rows and vertical

columns determine the dimensions of a matrix

[4 6 52 −3 −71 0 9 ]State the dimensions of each matrix.

A. B. C.[−4 13−3 ] [ 120

0.5]

EX 2 : IDENTIFYING A MATRIX ELEMENT

A =

Find each of the following elements:

𝒂𝟑𝟏 𝒂𝟐𝟐 𝒂𝟐𝟏 𝒂𝟏𝟏

EX 3: ORGANIZING DATA

China

Russia

U.S.

0 20 40 60 80 100

Column1ConsumptionProduction

Energy is often measured in British Thermal Units (Btu). 1. Write a 3 x 2 matrix to represent the data above.2. Rewrite the information as a 2 x 3 matrix.

EX 4: GYMNASTICSGymnast Floor

ExerciseVault Balance

BeamUneven

Bars

Amy Chow 9.525 9.468 9.625 9.400

Dominique Dawes

9.087 9.393 8.600 9.675

Kristin Maloney

9.525 9.225 9.312 9.575

Elise Ray 9.225 9.468 9.687 9.687

a. Write a matrix W to represent the information.

b. What are the dimensions of the matrix?

c. Which element represents Kristin Maloney’s score on the vault?

HOMEWORK

Organizing Data into Matrices

Worksheet