Almost every mathematics course will involve the study of functions. But why study it? To put it simply:
It's A Way To Model Phenomena

Functions (and relations) can represent most of the world's events. To demonstrate, the following are examples of relationships:
- The money put inside a vending machine and the drink that will come out of it
- The time spent studying and the resulting grades
- The distance traveled by a vehicle to its speed
- The radius of a circle to its area
- The amount of workforce and work accomplished
- The number of hours spent in the office and one's salary
- The number of customers and the sales generated
- The amount of water evaporated and the intensity of the rain
- The amount of sunlight and crop production
The examples above are just a handful of many phenomena we can represent using functions. Once we create these expressions, it can help us analyze, investigate, and predict behavior among these sets. It provides us with a model or a structure that leads us to the next point:
A Tool For Creating Solutions

Functions serve as a tool to help us develop solutions, improve products and services, or make logical choices. There are many things we can do with it once we create one. For example:
- When we know the link between hours in the office and work generated, we can find the optimum number of hours to ensure maximum output.
- We can find the right amount of water if we know the link between crop production and watering.
- We can predict sales if we have a relation between sales and the number of customers.
- We will know the optimum number of workers needed to finish a task if we see the connection between the worker and their job.
Some Examples
Let's consider more specific examples of the use of functions:
- In the study of projectile motion, we use two functions to describe the position of the projectile along its trajectory:
for horizontal and for vertical distance. We use the variable time - domain to get the object's position in both directions. Knowing these functions allows us to accurately predict where it will land and make adjustments when designing cannons and other equipment. - We can model bacteria growth as an exponential function
. As time (domain) goes by, the number of bacteria (range) grows exponentially: (the symbols and are constants). Analyzing how bacteria grows over time helps us how to culture or engineer it. - Engineers aim to study the behavior of internal forces on objects when subjected to loads. To achieve this, they express internal forces such as axial
, shear , moment , and torsion in relation to the object's position (x). Engineers specify the domain, which is the position (x) they want to investigate, and the function yields the range, which includes , , , and . Finding these will help engineers design the appropriate size and shape of the object.
Summary
Functions are a way to represent phenomena.
Functions are tools that help us create solutions.