You can evaluate a function at a certain point:
You can use the notation f(x,y), for example, to define a function with more than one variable:
Defining a function once allows you to use this function within other functions.
You can combine multiple functions together to create a separate function or you can create a composite function.
You can use a function on points! This example scales the points by a factor of 2, and translates -2 units vertically. Explore this graph.