# What is real analysis?

In 1665, Isaac Newton invented calculus. In 1727, he died a virgin. Now it's your turn.

Don't worry; the path is well-paved. Since Newton, other mathematicians have distilled the invention calculus into an area of study called real analysis.

This may sound like serious business. It's not.

## What are the main ideas of real analysis?

Analysis deals a lot with infinity and its associated funny business.

Fortunately, you don't have to be a genius who can see into the fourth dimension to understand infinity. Instead, we explore infinity the same way a 4 year old does: by asking annoying questions.

For example, if your little brother asks whether $\frac{1}{n}$ gets smaller than this 🤏 you can always throw a big $n$ at him and win. That's how we know it gets infinitely small.