You must have played around simple straight-line equations as of now. These are the nice equations that are simply solved for either x or y variables. Here, y equations are functions that can be plug into the calculator as well. So, the quick question that strikes to the mind here is why do we need the functional notation formula especially when we have nice “y” equations. Let us see how does the notation work here.

Take yourself back to the elementary school where teacher gave you worksheets to complete that contains the statements like “[ ] + 2 = 4” and you have to fill the value in the box. Once you will be getting older, the statement would be converted to “x + 2 = 4”, where you should simply find the value of x.

Why there is a need for switching from boxes to variables. There are how many total shapes that can be used for function notation and formula could be given as below for a trapezoid where a is the upper base, b is the lower base, and h is the height.

\[\ A = \frac{h}{2} (a + b) \]

If you wanted to express something more complicated, then also you can use these special notations. In most of the cases, A stands for area, h stands for height, a and b define the length and more similar variables too. Obviously, when equations are expressed in terms of variables, they are easier to understand and can give you more information than box notation.