“Functions Describe the World”

This powerful sentence comes from the book All the Mathematics You Missed by Prof. Thomas A. Garrity. It’s the way he introduces the concept of functions—and he does so with such conviction that he calls it a mantra every math student should chant before bed:

“Functions describe the world.”

What makes mathematics so remarkably useful is that seemingly unrelated real-world situations can often be described by the same type of function. This unifying power is what gives math its strength and versatility.

In one of his classes, Prof. Garrity explained this idea with such enthusiasm that it left a lasting impression. The modulation of his voice alone showed just how important this concept is.

Functions are one of the most powerful tools in mathematics. They show us how one thing affects another. Whether you're tracking the spread of a virus, modeling climate change, or forecasting business revenue, functions provide a lens to understand change over time.

They're not just about x and y—they're about inputs and outputs, cause and effect, prediction and planning. In programming, functions break down complex tasks. In economics, they model supply and demand. In science, they help us explain and predict natural phenomena.

When you know how to interpret and build functions, you gain the ability to see relationships clearly and think ahead. In a world shaped by data science, AI, and automation, mastering functions is like learning to read the blueprint of the future.

That’s why every math student should not only know what a function is, but also understand its significance—right from their school years. It’s more than just a topic in the syllabus; it’s a key to understanding the world.