Understanding Functions

A fuel station charges $1.06 for each liter of fuel. As more fuel is pumped into a vehicle, the total cost increases. This means the total cost depends on the number of liters pumped.

This relationship follows a simple rule: multiply the number of liters by $1.06 to get the total cost. For example, 10 liters of fuel costs $10.60.

This is an example of a function. A function is a rule that assigns exactly one output to each allowed input.

In this example, the number of liters pumped is the input because it is the value used in the rule. The total cost is the output because it is the result the rule gives.

The input is also called the independent variable because you can choose any allowed input value.

The output is called the dependent variable because it depends on the input value. For example, when the volume of fuel pumped increases from 10 liters to 15 liters, the total cost also increases.

So, functions help us describe real-world relationships and calculate outputs from given inputs.