This week we learned about function notation. It is a specific way of writing functions, which is a special type of relation where every x value only has one y value.

Written out, function notation looks something like this:

F(x)=2x+3

In the equation F is the name of the function and x is the input value. You could input a number into the equation and you would get a specific answer after you solve it.

To write a function from a table of values where, for example the x values are 1, 2, 3 and the y values are 5, 7, 9 you would follow these steps.

First, find out the rule. To do that, select a pair of x and y values to work with (let’s say 1 and 5). Then take the difference between the each y value (for example in the equation the y values increase by 2) and multiply that by the x value you chose (2×1). Then take the new number and see what you would do to it to get the original y value chosen (2+?=5). After that, write it out as an equation: (y=2x+3)

Now that you have the rule, you can write it in function notation. Write the name of the function, (usually f) then write x in parentheses to represent an input value. Finally write out the rule (2x+3). The final form should look like this: f(x)=2x+3.