2d Complete a function table based on a given rule and vice versa.

(DOK 1)

By: Deia Sanders

VocabularyFunction or Function Rule – a formula where the output depends on the inputExample:In the function rule y = 2x + 3 the value of y depends on the number you put in place of the x.

Function Table – a table of pairs of numbers that are a functionThe first variable is called the independent variable and the second is called the dependent variable.Input – the number you put in the place of the independent variable in a function rule

VocabularyOutput – the number that results when you put a number in a function or function rule

Domain – the set of all first numbers (input values)

Range – the set of all second numbers (output values)

Determine the Rule that Describes a Function

Which rule describes the function?

a) y = x – 1b) y = x + 1c) y = 2x + 1d) y = 2x – 1

X Y0 1

1 3

2 5 To be the correct equation you must be able to answer “true” for every pair.

Substitute the values of x and y into each answer choice. The values of x are the input values or the domain. The values of y are the output or the range.

Predict Values for a Function Table

A B3 64

7 14

20

Complete the table of values.

From the values shown, b is twice as large as a or b = 2a.When a = 4, b = 8.When b = 20, a = 10.

Complete the table of values.A B1 32 4

3 6

4

There is no consistent relationship between a and b. For an example like this, a graph may help to determine the missing values.

Turn to Handout #1

Come up with your own table!

X YX Y