It is very important for this lesson that you remember how to find the slope and the y intercept.

Let's Review

• functions are equations where any input value (often x) has only 1 output value (often y)

• You can represent a function as a graph, table or an equation

• If you have a graph you can use the vertical line test to check if it is a function

is there something you would like to go over before we continue?

Comparing Constant Rate of Change

you can compare two linear functions by comparing their constant rate of change (their slope)

The picture is an example from your book.

Linear and Non linear Functions

• a non linear function (like the function for the area of an object) does not have a constant rate of change

• a linear function will have a constant rate of change

• for these questions you will be asked if the function is linear or not.

Initial value

The other factor you can be asked to look at in the problems is the initial value. Because the initial value is going to be where the input is 0, it will be the y intercept on a graph or in an equation.

Let's try some examples