# Function rules

Views:

Category: Education

## Presentation Description

No description available.

## Presentation Transcript

### Function Rule:

Function Rule Algebra

### Review:

Review A relation is a set of ordered pairs. A function is a relationship that assigns exactly one output value (range) for each input value (domain). For each input there is only one corresponding output. 3 ways to view a function: Function rule Function table Graph REMEMBER: x = input = domain = independent y = output = range = dependent = also called f (x) at times

### Creating a function rule:

Creating a function rule Begin by analyzing the data you have – usually a table of values or series of points on a graph (which you can make into a table). Look for the pattern relating the x and y values. X Y 1 -1 2 0 3 1 4 2 Ask yourself, “What do I need to do to the x value, 1, to get the y value, -1? 2 to get 0? 3 to get 1? 4 to get 2?” You subtract 2 each time, therefore, y = x - 2

### Creating a function rule:

Creating a function rule What is the relation between x and y? 1 x 1 = 1 2 x 2 = 4 3 x 3 = 9 4 x 4 = 16 SO… y = x * x y = x 2 X Y 1 1 2 4 3 9 4 16

### Creating a function rule:

Creating a function rule Write a function rule to calculate the cost of buying apples at \$0.48 per pound. The y (range) value is the dependent variable so it is what we need to find – total cost. The x (domain) value is the independent variable that we will use to determine cost – the number of pounds bought. y = \$0.48 * the number of pounds of apples bought y = \$0.48x How much would 8.7 lbs cost? x = 8.7 y = \$0.48 (8.7) y = 4.176 round up to \$4.18