6th Grade Math Textbook, Progress

Functions and Ordered Pairs

14-4

Use the function rule to complete each function table.

Age in years (x) 5 8 10 20

Height in inches (y) 64 72 77 103

Rule: y
x 3

x y Ordered Pair


 6 
 6 

 3 
 9 (
6, 
9)

0 0 

 3 
 3 (0, 
3)

 2  2 

 3 
 1 (2, 
1)

Rule: y
x 5 Rule: y
x 4

x y Ordered Pair

 6??


 12??


 48??

x y Ordered Pair

 12??


 4??


 73??

These ordered pairs do not have an

obvious rule that relates the second

number in the pair to the first number.

One of the tallest persons in medical history

was Robert Wadlow, born in Alton, Illinois, in 1918.

On his 13th birthday, he stood 7 ft 1^34 in.

By age 17, he had reached more than 8 ft in height.

The function table below shows his height in inches

as a function of his age. A function is a set of

ordered pairs (x, y) in which there is only one

y-value for each x-value.

The pairs of numbers in the table can be written

as ordered pairs (x, y).

(5, 64) (8, 72) (10, 77) (20, 103)

You can write ordered pairs for a function because they

are related in a specific way, called the function rule.

The ordered pairs below are related by the rule: yx

3.

2.3

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