6th Grade Math Textbook, Progress

Graph Functions

14-8

You can use a rule or equation to make a function table and

use ordered pairs to graph points on a coordinate plane.

Graph the function y
 3 x4 on a coordinate plane using

integer values from 3 to 0.

To graph a function on a coordinate plane:


Make a function table.


Substitute values for xin the rule or equation.


Find the corresponding y-values.


Write an ordered pair for each x- and y-value.


Graph each ordered pair.


Connect the points.

 3 3(3) 4 
 9  4 
5 (3, 5)

 2 3(2) 4 
 6  4 
2 (2, 2)

 1 3(1) 4 
 3  4 
1 (1, 1)

0 3(0) 4 
 0  4 
 4 (0, 4)

x y
 3 x 4 (x, y)

x = 2.5

The graph of the function

y
 3 x4.

y
 3 x4 is a linear function, the

ordered pairs, (x, y), for the equation

are points that form a straight line.

You can also use the graph of y
 3 x4 to

estimate the value of yfor a given value of x.

Estimate the value of ywhen x
2.5.

When x
2.5, y
3.5.

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