Function tables with two-step rules

Introduction

In this lesson, we fill in a table with x and y values given a function rule with two-step rules. Usually the function rule is a linear equation in x and y. By giving different values to the independent variable x, corresponding values of dependent variable y are found. These x and y values are then put in a table. Thus a function rule with two-step rules is used to fill in a table with x and y values.

Example 1

Fill in the table using this function rule.

y = 5x 3

Solution

Step 1:

In y = 5x 3, for x = 0, y = 50 3 = 3; for x = 1, y = 51 3 = 2;

Similarly, for x = 2, y = 7; for x = 3, y = 12 and for x = 4, y = 17.

Step 2:

Making a table of x and y values we get

Inputx	Outputy
0	-3
1	2
2	7
3	12
4	17

Example 2

Fill in the table using this function rule.

y = 3x 3

Solution

Step 1:

In y = 3x 3, for x = 0, y = 30 3 = 3; for x = 1, y = 31 3 = 0;

Similarly, for x = 2, y = 3; for x = 3, y = 6 and for x = 4, y = 9.

Step 2:

Making a table of x and y values we get

Inputx	Outputy
0	-3
1	0
2	3
3	6
4	9