Section 4-1 Organizing Data Into Matrices

AA matrix (plural matrices) is a rectangular array of numbers written within brackets. AA matrix is represented by a capital letter and classified by its dimensions. TThe number of horizontal rows and vertical columns determine the dimension of a matrix.

3 columns 2 rows Matrix A is a 2 x 3 matrix.

Example 1 :Write the dimensions of each matrix. 3 rows x 3 columns

1 row x 3 columns4 rows x 1 column

EEach number in a matrix is a matrix element. AA matrix element is identified by its position within the matrix. AA lowercase letter with subscripts is used to name the element TThe subscripts represent the element’s row number and column number.

Example 2: Identify element b 13 in matrix B below. Element b 13 is 0.

Use matrix B to identify each matrix element. a. b 33 b. b 21 c. b

Data can be organized in a matrix to make it easier to interpret.

Ex 3 Three students kept track of the games they won and lost in a chess competition. They showed their results in a chart. Write a 2 x 3 matrix to show the data. YNYYNYY YYYYNYY NYNNYYN Ed Jo Lew Y = winN = loss

Wins Loss EdJoLew

Example 4 On the next slide is the table that shows the scores from the 2004 Olympics in Athens, Greece. Write a matrix W to represent the information. Use a 4 x 4 matrix.

Gymnast Floor Exercise Vault Balance Beam Uneven Bars Mohini Bhardwaj Courtney Kupets Courtney McCool Carly Patterson

Mohini Bhardwaj Courtney Kupets Courtney McCool Carly Patterson Floor Exercises Vault Balance Beam Uneven Bars

Which element represents Courtney McCool’s score on the vault? w 32