Why might function notation be important? Explore the reasons for function notation?

Answer 1

f(x)=y tell me the y-value for a particular x.

If you say something like y=7, do you mean the equation of a horizontal line or what x-value did you plug in and where to get y=7?

It's not as clear because you don't have a corresponding x-value. Now f(3)=7, tell me that when I plug in x=3, the corresponding y-value is 7.

Also, a function has to pass a vertical line test meaning that when you plug in an x-value, you will get only one y-value (not several y-values).